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kW to HP Converter

Convert kilowatts to horsepower with our free kW to HP converter — or switch between kilowatts, horsepower, and watts in any direction. One kilowatt equals 1.34102 HP, so a 5 kW motor is about 6.71 HP, and this page converts any of the three units instantly.

Common conversions

How it works

Kilowatts, horsepower, and watts all measure the same thing: power, the rate at which work is done or energy is used. A watt is the base unit: one watt is one joule of energy per second. A kilowatt is simply 1,000 watts, and a horsepower is an older unit defined as 745.7 watts. Because they all measure power, converting between them is a matter of multiplying or dividing by fixed factors, and this converter goes through watts as the common middle step.

The key relationships are:

To convert kilowatts to horsepower, multiply by 1.34102. To convert horsepower to kilowatts, multiply by 0.7457 — or divide by 1.34102, which gives the same answer. Watts sit underneath both: multiply kilowatts by 1,000 to get watts, and divide horsepower by 1,000 after multiplying by 745.7 to get kilowatts. Pick the "from" and "to" units in the converter above and it handles every combination, including watts to watts and the same-unit case.

Horsepower has a colourful history. It was defined by James Watt in the 18th century to sell steam engines to mine owners who were used to horses: he measured how much work a horse could do lifting coal and set one horsepower at 550 foot-pounds per second, which works out to 745.7 watts. The unit stuck because it gave buyers a comparison they understood — an engine rated at 10 HP did the work of ten horses. Kilowatts came later with the metric system and the spread of electricity, and they are now the standard unit for electric motors, solar panels, and EV batteries.

That history explains where each unit shows up today. Car engines are still quoted in horsepower in many markets, because buyers have a feel for what 150 HP or 300 HP means, while electric cars are increasingly quoted in kilowatts as well — a 150 kW EV motor is about 201 HP. Electric motors for pumps, fans, and tools are usually rated in watts or kilowatts, and a 1,500-watt heater is the same as a 1.5 kW heater, or about 2.01 HP. Generators are sold in both units, which is where a converter like this one earns its keep: a generator rated at 5 kW and one rated at 7 HP are close but not identical — 5 kW is 6.71 HP, so the 7 HP machine is slightly stronger.

One detail to watch is that there are two kinds of horsepower. The mechanical horsepower used here, 745.7 watts, is the standard for engines and motors. There is also a metric horsepower of 735.5 watts, used in some countries for car ratings, which makes 1 kW equal to 1.35962 metric HP. The difference is under 2 percent, but it is enough to matter when comparing spec sheets: a car quoted at 150 metric HP is about 110 kW, while 150 mechanical HP is about 112 kW. This converter uses mechanical horsepower throughout, and the table above is in mechanical HP.

Worked example

A buyer is comparing an electric motor rated at 5 kW with an older petrol engine rated in horsepower, and wants to know what 5 kW means in HP.

Step 1: Write down the power — 5 kW.
Step 2: Use the conversion factor — 1 kW = 1.34102 HP.
Step 3: Multiply — 5 × 1.34102 = 6.7051.
Step 4: Round to two decimal places — 6.71 HP.

That is the exact result this converter gives for 5 kW: 6.71 HP. The same method works in reverse: 100 HP converts to kilowatts by multiplying 100 × 0.7457, which gives 74.57 kW. And 1,500 watts converts to horsepower by dividing 1,500 ÷ 745.7, which gives 2.01 HP — the rating of a typical space heater, expressed three ways.

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