Converting kilowatts to horsepower: how many HP in one kW + principles and methods of calculation

How is engine power measured?

In practice, watts / kilowatts are most often used, and horses are used in only one area - calculating the power of an auto engine. The thing is that in Russia almost all car owners are required to pay a transport tax, and its size directly depends on the number of “horses” of the engine.

Consider when you need to use this or that horse for calculations:

• Metric - are the main units of measurement of engine power, since in practice they are used most often.
• English - used to calculate the power of cars that are manufactured in some British, American, Canadian, Australian and New Zealand factories.
• Electric - needed to calculate the power of a car with an electric and combined engine.

Instruments for measuring engine power

For the calculation, a special device called a dynamometer is used, which is connected directly to the car engine. To determine the strength of the engine, the car is placed on a special platform, and then an idle acceleration of the engine is performed with a connected dynamometer. Based on the measurement of some technical indicators (acceleration, acceleration speed, stability of operation, and others), during acceleration, the dynamometer determines the total power, and the results are displayed on a digital or analog screen.

Consider how they differ and which of these indicators is more reliable:

• Gross power - this indicator is measured when accelerating a “naked” car (that is, without a silencer, secondary shock absorbers and other auxiliary parts).
• Net power - this indicator is measured when accelerating a “loaded” car, taking into account all the necessary details that are needed for a comfortable ride.

Please note that when determining the transport tax, it is necessary to determine the “loaded” net capacity. The thing is that the gross power is usually 10-20% higher than the net indicator (after all, the car does not have to “accelerate” additional important details in this case).This trick is often used by unscrupulous manufacturers and marketers who want to put their car in a better light, what you need to remember when taking measurements

This trick is often used by unscrupulous manufacturers and marketers who want to put their car in a better light, which must be remembered when taking measurements.

What is horsepower

The LS unit was invented by James Watt at the end of the 18th century. It is assumed that this name is due to the fact that Watt wanted to prove the advantage of his steam engines over the more traditional draft labor - over horses. Popular legend says that after the first prototypes were built, one of the steam engines was bought by a local brewer who needed the engine to run a water pump. During the test, the brewer compared the steam engine with his strongest horse - and it turned out that the horse is 1.38 times weaker than the steam engine (and 1 kilowatt is exactly 1.38 hp).

What is kilowatts

At the beginning of the 19th century, horsepower began to be used to denote the power that one strong horse could produce at the limit. However, some engineers and scientists began to use not abstract horses as a starting point, but quite specific first Watt fixed-power machines. This practice took hold at the end of the 19th century, when watts were recognized as the unit of power. However, not all states have recognized the new units, so today horsepower is still used as an auxiliary or main unit of power.

Power rating - watt

The designation of horsepower in different languages ​​is different, for example:

• l. With. - in Russian;
• hp - in English;
• PS - in German;
• CV is in French.

Power P, as a system unit, in SI is measured in watts (W, W). This is 1 joule (J) of work that can be done in 1 second.

Electrical machines, thermal appliances, current and voltage sources are designated P in kilowatts (kW, kw). Since the watt is a small quantity, its multiple value of 1 * 103 is used. This measure was introduced into the designation in honor of the same James Watt. It measures both the power delivered by the energy source and the power consumed by consumers. The latter is also called power consumption. Its values ​​are applied to the cases of appliances and household appliances.

In order to calculate the amount of energy required to ensure the operation of all devices included in the 220 V network, you need to add up all the power consumption.

Formula for determining electrical power:

P = I*U

where:

• P is power, W;
• I – current, A;
• U - voltage, V.

This formula for determining power is correct for direct current. When calculating for alternating current, the values ​​of cosϕ are taken into account, which practically lies in the range from 0.5 to 0.7. This is the phase shift factor between current and voltage.

Despite the fact that it is universally forbidden to indicate the value of P in horsepower without indicating it in watts next to it, this can be encountered. Not to get confused in this will help the knowledge of the ratio and methods of translation l. With. to kw and vice versa.

Short story

In the early 19th century, Scottish scientist and inventor James Watt promoted the advantages of steam engines over horses. For the very first comparison, a horse-powered water pump was used. During the operation of the unit, the conversion of kilowatts into horsepower was first made, and the reference value was experimentally calculated.

As the basic calculation data, J. Watt took a barrel filled with water, the weight of which was 380 pounds, which was equal to 1 barrel (172.4 kg). The conditional working day was determined at 8 hours, two horses, weighing 500 kg each, participated in the work process. Their useful work was about 15% of the weight. During this period of time, the animals were able to walk 20 miles, that is, 28.8 km, at a speed of 2 miles per hour (3.6 km / h). In this case, the barrel was considered not as a unit of mass, but as a unit of force. Based on these data, the value of the traditional English horsepower was calculated, for which a simple formula was used: 1 hp \u003d 0.5 barrel x 2 miles / h. This unit of power lasted almost until the end of the 19th century, until a new unit was introduced - the watt.

Practical aspect

The amount of transport tax in Russia depends on the engine power. In this case, l is taken as the unit of account. s.: the tax rate is multiplied by their number. The number of payment categories varies by region. For example, in Moscow, 8 categories are defined for cars (prices are valid for 2018):

• up to 100 l. With. = 12 rubles;
• 101-125 l. With. = 25 rubles;
• 126-150 l. With. = 35 rubles;
• 151-175 liters. With. = 45 rubles;
• 176-200 l. With. = 50 rubles;
• 201-225 l. With. = 65 rubles;
• 226-250 l. With. = 75 rubles;
• from 251 l. With. = 150 rubles.

The price is given for 1 liter. With. Accordingly, with a power of 132 liters. With. the owner of the car will pay 132 x 35 = 4620 rubles. in year.

Previously, in the UK, France, Belgium, Spain, Germany, the vehicle tax depended on the number of “horses”. With the introduction of the kilowatt, some countries (France) abandoned the hp. With.completely in favor of the new universal unit, others (UK) began to take into account the size of the car as the basis of the transport tax. In the Russian Federation, the tradition of using the old unit of measurement is still observed.

In addition to calculating the transport tax, in Russia this unit is used for motor third party liability insurance (OSAGO): when calculating the premium for compulsory insurance of vehicle owners.

Another of its practical applications, now of a technical nature, is the calculation of the actual power of a car engine. When measuring, the terms gross and net are used. Gross measurements are carried out on the stand without taking into account the operation of related systems - a generator, a cooling system pump, etc. The gross value is always higher, but does not show the power produced under normal conditions. If the kilowatts indicated in the documents are converted to l. With. in this way, only the amount of engine work can be estimated.

For an accurate assessment of the power of the mechanism, this is impractical, since the error will be 10-25%. In this case, the actual performance of the engine will be overestimated, and when calculating the transport tax and OSAGO, prices will be increased, since each unit of power is paid.

The net measurement on the stand is aimed at analyzing the operation of the machine under normal conditions, with all auxiliary systems. The net value is smaller, but more accurately reflects the power under normal conditions with the influence of all systems.

A dynamometer, a device connected to the engine, will help you measure power more accurately. It creates a load on the motor and measures the amount of power delivered by the motor against the load.Some car services offer to use dynamometers (dynos) for such measurements.

Also, power can be measured independently, but with some error. By connecting a laptop with a cable to the car and running a special application, you can fix the power of the engine in kW or hp. at different speeds. The advantage of this option is that the program will display the calculation error on the screen immediately after the control estimate, and will also immediately convert from kilowatts to horsepower if the measurement was carried out in SI units.

Non-systemic units of measurement are gradually becoming a thing of the past. Power values ​​are increasingly specified in watts. However, as long as horsepower is being used, there will be a need to convert it.

Read more:

How many watts are in a kilowatt?

How to convert amps to watts and vice versa?

How to convert amps to kilowatts?

Determining the cross-sectional area of ​​a conductor by its diameter

What is the transformation ratio of a transformer?

Ways to convert kilowatts to l. With.

The mutual transition of these two units can be carried out in several ways:

1. Online convectors. There are software products for this, but you need access to the network. If you have the Internet, then the method is very fast and simple.
2. Tables. They contain values ​​that occur more often than others.
3. Formulas for translation. Used to “convert” physical quantities manually.

Numerical values ​​used in practice: 1 kW = 1.36 hp, 1 hp = 0.735 kW. It is easier to work with the first expression, and for simplicity, 1.36 is rounded up to 1.4. In this case, the error is small and if we estimate the power approximately, then its value can be neglected.

The way in which power was determined in fact affects the amount of power obtained by converting from one value to another.

Practically converting kW to hp. will look like this:

90 kW x 1.4 = 126 hp and reverse action: 140 hp : 1.4 = 100 kW.

For more accurate calculations in order to determine how much horsepower is still in a kilowatt, a coefficient of 1.35962162 is used.

Practical aspect

The amount of cash tax on the car depends on the horsepower indicated in the vehicle's data sheet. The cost of the insurance policy is also directly subordinated to this figure. In order to estimate their costs in advance, motorists have to convert conversions of kW to hp and vice versa.

This task can be easily handled by online calculators kW to hp. With. Many of these programs work easily. In the program window that opens, the calculator has two working positions. A known value is entered into one of them, and the desired result is displayed in the other working field of the program. It remains only to click the mouse and convert kW to l s.

Important! The values ​​obtained, both in manual calculations and on the online calculator, can have a capacity of up to four decimal places. In this case, it is necessary to round the numbers when converting power from kW to l

With. and back.

Number Rounding Rule

Rounding will help you understand which power level the car belongs to. Taxation (transport tax) has a stepped price palette. For example, with a car up to 100 liters. With. one tax is taken, starting from 101 horsepower, the amount of taxation increases.

Table of transport tax depending on the power of the car

Where did they get 0.735 kW

Horsepower, like any other unit of measurement, must have justifications, both theoretical and practical. The scientist decided to determine the relationship between watts and hp. based on the uplift of people and mining from coal mines.

The barrel used for this purpose was pulled out by two animals. They dragged a rope for 8 hours without a break, which, by means of a block, pulled up the prepared container. Watt, given that the average weight of such a load is 180 kg, in practice came to the conclusion that her horse should be dragging 75 kg at a speed of 1 m / s. In this case, 1 HP equals 320,000 pounds-pounds per minute. After rounding the result and taking into account the speed of free fall (g-9.8 m / s2), he got an indicator of 735.55 watts or 0.735 kW.

Interesting!

The engineer made calculations taking into account the fact that the horse will be able to work for a long time. In the case of a short period of time 1 HP. will be about 1000 kgf per m / s = 9.8 kW. This value is formal and is used only for the correct calculation of the amount of taxes.

Power rating - watt

In the SI system, a watt is a measure of the amount of power required to do 1 joule of work in a given amount of time. In this regard, it became possible to convert kilowatts to horsepower and vice versa, since this is the same unit of measurement, only multiplied by 1000. It indicates the amount of energy consumed by any device per unit of time.

In the Russian Federation, the value of horsepower is brought to a single standard. There was such a parameter as metric horsepower, which is 735.49875 W, that is, less than one kilowatt.This made it possible to easily convert kW to hp, a table for this purpose was developed in a very wide range. In exact mathematical calculations, this value is practically not used.
This parameter is widely used in calculating the cost of OSAGO and tax on vehicle owners. This is especially true for some foreign-made cars, the data of which is displayed in modern units. In such cases, you have to calculate how many horsepower in kilowatts in order to correctly perform the necessary calculations.

Since the watt unit of power has a large number of derivatives, not all of them can be reflected in a regular table. In such a situation, you can convert kilowatts to horsepower online. It is enough just to enter the necessary data in the appropriate windows and the online calculator will convert hp to kW almost instantly.

This technique is very effective for a large number of technical calculations. They are especially in demand in design, when it is necessary to determine in advance the exact number of machines and mechanisms for certain scopes of work. The same applies to organizations involved in cargo transportation.

Amperes to Watts Conversion Calculator

Online calculator for calculating current by power

Translation of data types gigabyte, megabyte, byte, bits

LED luminous flux online calculation

Online color coding of resistors

Online transformer calculation calculator

How strength is measured in Russia and in other countries

Now in different countries several types of units with a similar name are used. At the same time, not only the name of this quantity differs, but also its indicator.

So, horsepower is distinguished:

• metric - 735.4988 W;
• mechanical - 745.699871582 W;
• indicator - 745.6998715822 W;
• electric - 746 W;
• boiler room - 9809.5 W.

The unit of power calculation Watts is international.

Attention!

The term "horsepower" in Russia is used only to calculate OSAGO insurance and pay vehicle tax on a car. In other cases, this measurement measure is not used, but they do not intend to abandon it yet.

The first variety is typical for many European countries. Mechanical power is inherent in the United States of America and England. Also in the USA they also use boiler and mechanical HP.

What is the difference between these units of measurement?

Officially for various calculations, in the Russian Federation 735.49875 Watts, so it will not be difficult to recalculate horsepower to watts and determine how many horsepower in a kilowatt. For example:

10 HP * 735.49875 = 7354.9875 W - There are 7354.9 W in 10 horsepower.

100 l / s * 735.49875 \u003d 73549.875 W - At 100 horsepower - 73549.8 W.

1000 l / s * 735.49875 \u003d 735498.75 W - In 1000 horsepower - 735498.7 W or 735.4 kW.

If you want to make an accurate calculation of the number of watts in horsepower, you can use a calculator with which you can make calculations using very large numbers. Knowing how many kilowatts is 1 horsepower, you can calculate the inverse ratio.

1 l / s / 7354.9875 W \u003d 0.001359 l / s - there are 0.001359 horsepower in one watt. By multiplying this value by the number of watts, you can determine the exact amount of horsepower in the device or unit.

Table for translation l. With. in kW

To calculate the motor power in kW, you need to use the proportion 1 kW \u003d 1.3596 liters. With. Its reverse view: 1 l. With. = 0.73549875 kW.This is how these two units are mutually translated into each other.

kW	hp	kW	hp	kW	hp	kW	hp	kW	hp	kW	hp	kW	hp
1	1.36	30	40.79	58	78.86	87	118.29	115	156.36	143	194.43	171	232.50
2	2.72	31	42.15	59	80.22	88	119.65	116	157.72	144	195.79	172	233.86
3	4.08	32	43.51	60	81.58	89	121.01	117	160.44	145	197.15	173	235.21
4	5.44	33	44.87	61	82.94	90	122.37	118	160.44	146	198.50	174	236.57
5	6.80	34	46.23	62	84.30	91	123.73	119	161.79	147	199.86	175	237.93
6	8.16	35	47.59	63	85.66	92	125.09	120	163.15	148	201.22	176	239.29
7	9.52	36	48.95	64	87.02	93	126.44	121	164.51	149	202.58	177	240.65
8	10.88	37	50.31	65	88.38	94	127.80	122	165.87	150	203.94	178	242.01
9	12.24	38	51.67	66	89.79	95	129.16	123	167.23	151	205.30	179	243.37
10	13.60	39	53.03	67	91.09	96	130.52	124	168.59	152	206.66	180	144.73
11	14.96	40	54.38	68	92.45	97	131.88	125	169.95	153	208.02	181	246.09
12	16.32	41	55.74	69	93.81	98	133.24	126	171.31	154	209.38	182	247.45
13	17.67	42	57.10	70	95.17	99	134.60	127	172.67	155	210.74	183	248.81
14	19.03	43	58.46	71	96.53	100	135.96	128	174.03	156	212.10	184	250.17
15	20.39	44	59.82	72	97.89	101	137.32	129	175.39	157	213.46	185	251.53
16	21.75	45	61.18	73	99.25	102	138.68	130	176.75	158	214.82	186	252.89
17	23.9	46	62.54	74	100.61	103	140.04	131	178.9	159	216.18	187	254.25
18	24.47	47	63.90	75	101.97	104	141.40	132	179.42	160	217.54	188	255.61
19	25.83	48	65.26	76	103.33	105	142.76	133	180.83	161	218.90	189	256.97
20	27.19	49	66.62	78	106.05	106	144.12	134	182.19	162	220.26	190	258.33
21	28.55	50	67.98	79	107.41	107	145.48	135	183.55	163	221.62	191	259.69
22	29.91	51	69.34	80	108.77	108	146.84	136	184.91	164	222.98	192	261.05
23	31.27	52	70.70	81	110.13	109	148.20	137	186.27	165	224.34	193	262.41
24	32.63	53	72.06	82	111.49	110	149.56	138	187.63	166	225.70	194	263.77
25	33.99	54	73.42	83	112.85	111	150.92	139	188.99	167	227.06	195	265.13
26	35.35	55	74.78	84	114.21	112	152.28	140	190.35	168	228.42	196	266.49
27	36.71	56	76.14	85	115.57	113	153.64	141	191.71	169	229.78	197	267.85
28	38.07	57	77.50	86	116.93	114	155.00	142	193.07	170	231.14	198	269.56

What is used for

The amount that you have to pay as a transport tax depends on how the engine power is indicated in the vehicle registration certificate in horses. The price of an insurance policy is also related to this indicator. To determine in advance the approximate amount of the contribution, the car owner can convert kilowatts to horsepower and vice versa.

An online calculator is quite suitable for this. It is easy to use such a program: two work zones will appear in the window that opens, in one of which you need to enter a known value. In this case, the result will be displayed in another.

Attention!

When calculating, a number with 4 decimal places can be displayed. If this happens, then the total value will need to be rounded up.

With the help of rounding, it will also be possible to understand what power the car belongs to.

This is important because tax is calculated in steps

For example, up to 100 hp the amount will be one, and with an indicator of 101 "horses" you will have to pay more.

Passenger car engine power, h.p.	Tax rate, rub.
How many years have passed since the date of manufacture of the car
maximum 5	5-10	10-15	over 15
up to 100	25	23	22	20
101-125	33	32	31	30
126-150	35	34	33	32
151-175	47	46	45	44
176-200	50	49	48	47
201-225	65	63	62	60
226-250	72	70	68	65
251-275	90	85	80	75
276-300	105	100	95	92
over 300	135	125	120	115

The table will also help to more accurately determine the final amount of taxation.

Horsepower is a value that is used to determine the power of a car. This is an important indicator that should be considered when buying a vehicle, because. the amount of transport tax directly depends on it.

What is horsepower and how did it come about

Why did horsepower come to be used as a unit of power? How is it expressed in terms of other units? J. Watt proposed in the 18th century. device for pumping water from mines. However, it was necessary to somehow explain to the owners of the mines what exactly he offers them to purchase, what are the advantages of the invention.

To evaluate the power of the new engine, such an event was taken. The horse was harnessed to an ordinary pump for lifting water, which worked with the help of horse traction. Then they estimated exactly how much water the horse would lift in 1 day.

Then they connected a steam engine to this pump and saw the result obtained within 1 day of work. The 2nd number was divided by the 1st, using these numbers to explain to the owners of the mines that the pump can replace so many horses. The power value obtained as a result of the 1st experiment was made a measure, denoting it to him with the phrase "horsepower".

Thus, the wording "horsepower" appeared thanks to the official inventor of the steam engine, engineer J. Watt from England. He had to make a clear demonstration of the fact that the machine he created was capable of becoming a substitute for many horses. For the sake of this, it would be necessary to somehow determine in units the work that the horse is capable of performing in a certain time.

Through his observations in coal mines, Watt demonstrated the ability of an average horse to lift approximately 75 kg of weight from a mine at a speed of 1 m/s for a long time.

horsepower in a car

The kW value divided by 0.735 is the horsepower in the car. It is comparable to the action performed in 1 s in order to lift a 75-kilogram weight by 1 m.At the same time, gravity is also taken into account.

The greater the engine power of the car in relation to the mass of the vehicle, the more efficient it is. In other words, the less the body weighs, the greater the power rating and the greater the acceleration of the car.

In order to convert the passport power of a certain car from kilowatts to horsepower, it is necessary to divide the existing value by 0.735

For example, the Jeep Wrangler has 177 hp. and a gross weight of 2.505 tons. The ratio of power to gross weight will be: 177: 2505 = 70.56. Acceleration to hundreds of kilometers per hour - 10.1 s.

If you take a powerful Ferrari 355 F1 with a 375 hp engine. and weighing 2.9 tons, then the ratio will be 375: 2900 = 0.129. Acceleration to 100 km / h - 4.6 seconds.

This is a table with which you can very easily convert horsepower to kilowatts without any calculations.

The designation of horsepower in different countries is not the same. Whereas in Russia it is hp, in English-speaking countries it is hp, in the Netherlands it is pk, in Germany it is PS, in France it is CV.

When the kilowatt was introduced, France stopped using CV and completely switched over when calculating the tax on these new units of power. In the UK, the dimensions of the car were taken as the basis for the vehicle tax.

In Russia, in addition to the transport tax, hp. used when calculating the amount of payment for insurance of the iron "horse" (OSAGO). Apply HP and when determining the actual power of the car's engine. At the same time, such terms as gross and net are in use.

The first indicator is measured at the stand and the operation of the cooling pump, generator and other related systems is not taken into account.Its value is always higher than the second parameter, but does not represent the power generated under normal circumstances.

If this method is used to convert the kilowatts indicated in the passport, then only the amount of motor operation will be established. To accurately estimate its power, it is impractical to use this method because of the large error, which is from 10 to 25%. Since the performance of the motor will be overestimated, the transport tax will also be large.

The stand gives out the net value, taking into account the auxiliary systems. The parameter obtained in this way corresponds more closely to the power under normal conditions. A device such as a dynamometer will be able to determine the power even more accurately.

The more horsepower an engine has on a car, the more tax the owner of the vehicle has to pay, so every motorist must be able to convert power from kW to hp. and vice versa

From how much hp. the motor of the car accelerates, the classiness of the car and its dynamic characteristics depend.

If there is no technical documentation for the car, and you need to know its power, you can do this in two ways.

#1: Vehicle power determination method

To determine the power in traditional horsepower using this option, you need quantities such as torque, engine speed. You can find them in the instructions or on the Internet, if you indicate the appropriate brand of car.

Further, the found parameters are multiplied. The following expression is used for the calculation:

(RPM x T) / 5252=HP

In it, RPM is the engine speed, T is the torque, 5.252 is the number of radians per second.So, one of the models of the Hyundai Santa Fe car has a torque of 227 at a speed of 4000, so 227 x 4000 \u003d 908,000. The result is divided by 5252 and get the power in horsepower:

908,000 : 5252 = 173 hp

#2: Power Calculation Method

On a car engine, voltage is usually indicated in volts, current in amperes, and efficiency in percent.

Using this data, calculate the engine power in hp. according to the formula:

(V x I x efficiency) : 746=HP

Efficiency is translated into a decimal fraction - in the form of a decimal fraction of 82%.

Voltage, current, efficiency are multiplied, then the result is divided by 746. So, if the voltage is 240 V, the current is 5 A, the efficiency is 82%, then the power in hp. will be 1.32 hp.

The difference between the ratio of kilowatts and horsepower with different measurement methods

The way you measure actual power directly affects the numbers you get when converting kilowatts to horsepower.

This is especially true for calculating the real power of vehicle engines.

There are concepts of gross and net horsepower.

When carrying out gross measurements, the engine power is evaluated at the stand. The operation of related systems that ensure the operation of the machine as a whole is not taken into account - a generator, a cooling system pump, and so on.

Measuring the net power on the stand is carried out with reference to its operation under normal conditions, that is, with all auxiliary systems.

Accordingly, the first value will always be larger in numbers, but will not show the real power of the mechanism.

As a result, if the kilowatts indicated in the documentation for the technical device are converted into horsepower in the first way, it is possible to estimate the amount of work performed exclusively by the engine.To obtain real information about the power of a transport or other unit, this will not be very useful, since the error will be from 10 to 25%.

Also, such measurements are unprofitable for determining the actual performance of the engine when calculating taxes on transport and purchasing OSAGO, since higher rates are provided for higher rates, and the calculation is made taking into account each horsepower.

To accurately measure the value, there are special devices - dynamometers. The services of the so-called dynos (dynos) are provided by some car services.

In addition, rather expensive electronic devices are produced that are installed directly in the vehicle.

Independently, but with some error, you can measure the power of the engine in kilowatts or horsepower using specialized applications for computers by connecting a laptop via cable to the car and measuring the performance at different speeds. The measurements will contain some error, which the program also informs about after the calculations.

How to convert kW to hp

There is more than one option that allows you to convert kilowatts to horses. To do this, you can use various means:

• An online calculator will help you quickly convert kW to l s. This method is the easiest and fastest. Therefore, if you need to answer the question, how many hp are there in 1 kW, the answer will be immediate. But this method has one drawback - it requires a permanent connection to the Internet;
• lookup tables that contain the most common values ​​and are always at hand when needed;
• conversion formulas - knowing exactly what the units correspond to, you can easily convert kilowatts to hp. So, one horsepower is equal to 0.735 kW, and 1 kW is equal to 1.36 hp.

In the latter option, the second parameter is more often used, because values ​​greater than one are much easier to work with. To calculate, you need to multiply the kilowatt indicator by this coefficient. For example, if the power is 90 kW, then in horsepower it will be 90x1.36 \u003d 122.

The history of the appearance of the HP unit

Miners from 18th century Britain used a Newcomen steam engine to pump water out of mines. This device wanted to improve and increase its performance physicist Watt. As a result, its efficiency increased by 4 times. In addition, he made it so that the piston began to work in both directions, he also managed to develop a mechanism for transmitting movement from the piston to the rocker. Thus, it was possible to create a steam engine that converts the translational movements of the piston into rotational ones.

As a result, a whole revolution took place, thanks to which it became possible to use the installation in different areas. Already by 1800, Watt and his companion produced almost 500 such devices. However, less than 25% were used as pumps.

The need to sell their products of labor led to the need to determine its technical parameters. therefore, the main indicator that interested buyers was the power of the heat engine. James Watt wanted to demonstrate how many horses a steam engine would replace and coined the term "horsepower" - hp.

The idea for such a comparison came to the mind of an inventor from Scotland after a brewer bought an engine in 1789 and decided to compare its performance in turning a water pump with the same work of one horse. The craftsman wanted to prove that the installation was ineffective and as a result forced one of his hardiest horses to wear out. Watt did not lose his head and answered the challenge, only slightly exceeding the performance of one animal.

How to check battery capacity?

Very often, the owner of a used battery is faced with the task of determining its residual capacity. The classic and must be paid tribute to the most reliable and effective way to check the actual capacity of the battery is considered to be a test discharge. This term refers to the following procedure. The battery is first fully charged, after which it is discharged with direct current, while measuring the time during which it is completely discharged. After that, the battery capacity is calculated using the already known formula:

Q= I T

For greater accuracy of the calculation, it is better to select the value of the constant discharge current in such a way that the discharge time is about 10 or 20 hours (this depends on the discharge time at which the nominal capacity of the battery was calculated by the manufacturer). Then the obtained data is compared with the passport ones, and if the residual capacity is 70-80% less than the nominal one, the battery must be replaced, as this is a clear sign of severe battery wear and its further wear will proceed at an accelerated pace.

The main disadvantages of this method are the complexity and laboriousness in implementation, as well as the need to decommission batteries for a sufficiently long period of time. Today, most devices that use rechargeable batteries for their work have a self-diagnosis function - a quick (in just a couple of seconds) check of the status and performance of energy sources, but the accuracy of such measurements is not always high.

What is kilowatts (kW)

Watt is the SI unit of power, named after the inventor J. Watt, who created the universal steam engine. The watt was adopted as the unit of power at the 2nd Congress of the Scientific Association of Great Britain in 1889. Previously, horsepower, which was introduced by J. Watt, was mainly used for calculation, less often - foot-pounds / min. The 19th General Conference of Measures in 1960 decided to include Watt in the SI.

One of the main parameters of any electrical device is the power it consumes. For this reason, on each electrical device (or in the instructions attached to it), you can read the data on the number of watts that is required for the operation of the device.

Distinguish not only mechanical power. Thermal power and electrical power are also known. 1 watt for heat flow is equivalent to 1 watt of mechanical power. 1 Watt for electrical power is equivalent to 1 Watt of mechanical power and is essentially the power of a direct electric current with a strength of 1 A, which does work at a voltage of 1 V.

How to use the online calculator

To use the proposed online calculator for converting power from one unit to another, just select a unit, enter the number of power units in this unit and press the button for receiving the result on the display.

I like 4 I don't like 1

Read more:

Current to Power Conversion Calculator

Car engine power calculator

Online fraction converter, conversion of dozens, percents, ppm and other units

Online area converter, area units in different systems, their quick conversion

Calculator for converting pressure in bar to pressure in megapascals, kilogram-force, pound-force and amospheres

Online converter of number systems, translation between decimal, binary, octal and other systems