Kw to hp (Conversion & Information)

Kilowatts, often symbolized as kW, is an SI unit (International System of Units) of power. Usually, a watt is the base unit of power- it was named after the Inventor James Watt from Scotland. Kw to hp calculator is on this page.

Like other SI units, the prefix Kilo stands for a thousand; therefore, a kilowatt is equivalent to a thousand watts or a thousand joules per second. On the other hand, HP is a standard symbol for horsepower.

This is a unit of measuring power or rate at which work is performed. With that said, in this article, I shall be answering Kw to hp question.

KW to hp Question

How many kW is a 1 hp motor?

One mechanical horsepower equals 0.7457 kilowatts. The mechanical horsepower also referred to as the imperial horsepower, is often defined as 745.7 watts or 550 ft.lbs/s. On the other hand, the metric horsepower is defined as 735.5 watts or 75 kgf.m/s. When rating an electric motor, 1 horsepower equals 746 watts.

How do you calculate kW to HP?

Since 1 mechanical horsepower is equivalent to 0.7457 kilowatts, you will need to use these values to convert kW to HP. The conversion of kilowatts to horsepower is;

P(hp) = P(kW) / 0.745699872

For instance, converting 20Kw to horsepower will be;

P(hp) = 20kW / 0.745699872= 26.82 hp.

How many kW is a 5hp motor?

When converting horsepower to kilowatts, you cannot use the P(hp) = P(kW) / 0.745699872 formula; however, you will need to use P(kW) = 0.745699872 ⋅ P(hp). Therefore, to find the amount of kilowatts in a 5 horsepower motor, you will go ahead and calculate as follows;

P(kW) = 0.745699872 ⋅ 5hp= 3.72849936 kilowatts.

According to the above calculation, a 5 horsepower motor features 3.72849936 kilowatts.

Kw to hp (Conversion & Information)

Why is 1Hp equal to 746 watts?

First and foremost, Watts and HP are both used units of power. When it comes to power, it can be either mechanical or electric, and it can also be converted between these two.

The conversion will be less than 100% efficient. And it is due to the historical reason that power isn’t measured in HP but in Watts, like how a tire’s width is measured in mm while rim diameter is measured in inches.

Therefore, 550 ft.lbs/s converted to metric will be 550 x 0.3048 x 4.44822 Newton meter/s. This is equivalent to 745.7 Newton meter/s also referred to as watts. A foot is 0.3048 meters therefore;

· 1 horsepower= 550 ft.lbs/s

· 1 lbs.=4.44822 Newtown

· 1 ft.= 0.3048 meters.

· 1 HP= 550 x 4.44822 x 0.3048 meters

· 1 HP= 745.69 Newton meter/s

Therefore, when converted to nearest hundreds, 745.69 Newton meter/s second becomes 746 Newton meter/s. As a result, one horsepower will not be less than 746 watts; therefore, using 1 kW is approximately 75% efficient, perfect for a motor of that particular size.

Kw to hp Calculator

Relationships Between kW and Hp

Horsepower (Hp) is a metric unit of power; Kilowatt-hour (kW), on the other hand, is a measure of energy. To go from HP to KW, you need to assess how long the power is being released or exerted. Let us take an example of a 100HP engine operating/running for six minutes to use a pointedly less KW than the same machine running for one hour.

Hp to kW formula

To convert/calculate for HP in a machine, you should constantly subject all of your findings into the following formulas;

KW=hp(I) x 0.7457

Where KW is Kilowatt per hour of a given engine/motor

HP is the given horsepower

0.7457 is a constant of the power conversion


Calculate the number of 10 mechanical horsepower to kilowatts of a turbo engine operating at a normal rate?


In questions of this kind, you need to be keen on the operational rates of the engine; for our case, it is a normal operation, and for any engine, the operation is given by;

KW=hp(I) x 0.7457

10hp (1) = (10 x 0.7457) = 7.457 Kw

Note; Hp to kW conversions are subjected to the formula unless otherwise or indicated by the designer /questions.

Metric Hp to kW

When converting metric hp to kW use the following formula;

kW=hp(M) x 0.735499

Since one hp(M) is equal to 0.73545kW, the conversion formula should always give you values of kW per hour.

Example; Calculate the power needed for a horsepower engine rated at 10hp?


10 hp(M)=9(10 x 0.735499) =7.35499kW

kW to hp calculation

There are some scenarios where you will be required to calculate the required horsepower of a given engine. For instance, you’re a tech or mechanical personnel in your company, and you are working on a project that requires you to procure an engine, car, or motor to work in your project.

So, how do you identify the right engine for your project? The answer is simple by calculating your project needs in terms of hp and then buying an engine that is above that value or exactly the same.

KW=hp(I) x 0.7457…………………………………1

In order to get hp (I), we make hp the subject of the formula that is by dividing both sides with 0.7457

Hp (I) is given by;

Hp (I)= kW/0.7457………………………………2

Therefore, the general formula is given by hp(I)=kW/0.7457

For example; In a ten-floor building project, a pump is to be bought to supply water to the working sites and for other uses. Calculate the required horsepower when the operating power line is 4400kW?


Hp (I) = kW/0.7457

Hp= 4400/0.7457=5900.4961Hp

Buying Recommendations; The site working requirement is 5900.4961. The required engine or motor should be higher than this, which means you will buy a 6000Hp pump.

hp to kw/hr

When converting or calculating the number of horsepowers used in a given time, you will be required to multiply the given HP value by the total time the engine has been working.

For instance, if you have a 30-horsepower engine running for four hours, you would multiply thirty by four to get 120HP. You can simplify this even further by multiplying the number of HP per hour by 0.7457KW/hr.

To convert your answer to KW/hr. In this case, you would subject your values to 60 minutes then multiply it by 0.7457 to get a general value of 44.74200.

In order to convert hp to kw per hour, you need to subject all the findings to a;

Hp (I) =(kW/0.7457) x 60

Final verdict

Understanding how to convert kW to HP and vice versa is vital. After going through this article, I hope you have found it beneficial and understand how to covert the two units of power with ease. In addition to that, I hope you have understood why is 1Hp equal to 746 watts.

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