What you need to know about kilowatts and horsepower for your vehicle

When we are speaking about the vehicles we are used to thinking about the engine in two terms: horsepower and torque. Converting kilowatt to horsepower can be tricky. Today we have the development and popularity of the electric vehicles, so now the power of electric motors is specified in kilowatts, and here come out the questions like why we have this difference, can these power ratings be compared and is there any way to convert kilowatts to horsepower or converting kw to hp?

Before everything else, here is one simple conversion from horsepower into kw:

1 horsepower (hp) is equal to 0.7457 kilowatts (kW), as well as 1 kW equals 1.337 hp. The 1.34 and 0.745 are the kw to horsepower conversion factor.

You’re able to do the calculations by yourself (hp x 0.745 as well as kW x 1.34) or perhaps you may use an online kw to hp conversion chart. Here is one example of a good online kilowatt to horsepower chart:

Why the differences in the power measurements?

The reason why these kinds of power measurements are different is because they are distinctive types of power.

Single kilowatt has 1,000 watts, and this is a unit of power named by the Scottish engineer James Watt. However, he did not develop the steam engine, but still, he has patented a few modifications about the Newcomen steam-engine which was used to pump water out of the mines. In those days, these mine pumps happened to be driven by something that was called a “horse engine.”

Watt (in partnership with other individuals) found that single horse is able to lift 550 pounds (of water) one foot in a second, and that’s how it became the definition of 1 horsepower.

Keep in mind that the horsepower is a determined number, which is identified with the factors like weight, time and distance. We have a combination of weight and distance anytime we calculate the torque; a power turning around a shaft. When a vehicle engine moves a shaft to turn, we calculate the pounds of force produced perpendicular to and 1 foot away from the center of the shaft.

This is a straight measuring of foot-pounds of torque. In order to get horsepower, we must know what number of foot-pounds per second the engine can produce.

For this we have a formula:

torque x rpm divided by 5252. The last number is a continuous component that is a result of converting rpm into feet per second.

Horsepower is actually a measurement of mechanical power. When we speak about an electric motor, the power is described by calculating the electric energy that is created to take.

Whenever we want to measure the electric current, we are actually calculating the flow rate of the electrons moving through a circuit. One ampere is equivalent to a particular quantity of electrons which are moving per second (in case you want to know the correct number is 6.241 × 1018 electrons).

This flow rate is dependent in part regarding the electrical pressure, which is pushing the electrons via the circuit, and this is known as voltage. Also included here is the resistance in the circuit which is opposing the flow of the electrons. So, with the increasing both the voltage or amperage grows the quantity of electricity and the power in the circuit.

Making it simple to measure and also deal with electrical power, we just multiply volts x amps and name the result as watts. That being said, when 12 volts are flowing at 10 amps we  have the same 120 watts of power created when 120 volts flowing at 1 amp. To be more clear, the additional watts that are available in a circuit, the additional resistance it can overcome.

Convert kw to hp – it´s simple:

The horsepower is an outdated, but still commonly used in everyday unit of power. As a unit symbol hp is used.

By 2009, could be specified in the advertisement hp only in addition to kilowatts (kW). Since the last amendment of EU Directive 80/181 / EEC, which entered into force on 1 January 2010, the sole performance of hp and all other non-SI units throughout the EU is no longer allowed.
(Source: Wikipedia.org)

It is often necessary to the specified value of kw to hp – or vice versa – to convert. For example, is often expressed in letters, only the vehicle power in kw (kilowatts).
For this you can use either the simple conversion formula, or our simple, above, take KW / HP-Conversion service.

kW to hp conversion with our converter