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Horsepower to kilowatts

Multiply horsepower by 0.7457 to get kilowatts.

1 hp = 0.7457 kWNIST SP 811
hp
149.14kW

200 hp = 149.14 kW

How to convert horsepower to kilowatts

The kilowatt is one thousand watts — the metric unit for engine and appliance power. The horsepower is mechanical (imperial) horsepower, about 745.70 watts.

Worked example — 200 hp: 200 × 0.7457 = 149.14 kW.

Horsepower to kilowatts table

Common conversions. The reverse table is on kilowatts to horsepower.
HorsepowerKilowatts
1 hp0.7457 kW
50 hp37.285 kW
100 hp74.57 kW
150 hp111.855 kW
200 hp149.14 kW
250 hp186.425 kW
300 hp223.71 kW
400 hp298.2799 kW
500 hp372.8499 kW

Reverse and related

About horsepower and kilowatts

Horsepower (hp)

1 hp = 0.7457 kW

Definition. Mechanical (imperial) horsepower, about 745.70 watts

History and origin

Horsepower was coined by James Watt in the 1780s to compare his steam engines to the draught horses they replaced, based on the work a horse could do. Mechanical horsepower is about 745.7 watts.

Current use

Horsepower rates car and engine power in the United States and United Kingdom.

Source: NIST SP 811, App. B (power). Mechanical hp = 550 ft·lbf/s ≈ 745.70 W; metric hp (PS) = 75 kgf·m/s = 735.49875 W

Kilowatt (kW)

1 kW = 1.341 hp

Definition. One thousand watts — the metric unit for engine and appliance power

History and origin

The kilowatt is one thousand watts, a metric multiple of the SI power unit. It gives practical numbers for engines and appliances.

Current use

Kilowatts rate car engines outside the United States, large appliances and electric-vehicle charging.

Source: NIST SP 811, App. B (power). Mechanical hp = 550 ft·lbf/s ≈ 745.70 W; metric hp (PS) = 75 kgf·m/s = 735.49875 W

Where people use this

Horsepower: car and engine power in the US/UK. Kilowatts: car engines outside the US, appliances, EV charging. A 200 hp engine is about 149 kW.

How we know this is right
The factor is fixed by the standards that define the units, not chosen — so it is exact, not a measurement:
1 kW = 1.34102209 hp, so 1 hp = 1 ÷ 1.34102209 = 0.7457 kW.

Every value is carried to full double precision; the display is rounded.

Both units are defined in NIST SP 811, App. B (power). Mechanical hp = 550 ft·lbf/s ≈ 745.70 W; metric hp (PS) = 75 kgf·m/s = 735.49875 W.

Questions people ask

How many kW is 1 hp?

One horsepower is about 0.746 kW. To convert hp to kilowatts, multiply by 0.746.

How many kW is 200 hp?

A 200 hp engine is about 149 kW, and 100 hp is about 74.6 kW.

How do you convert hp to kW?

Multiply the horsepower by 0.746, so a 300 hp engine is about 224 kW.

How many kW is 400 hp?

400 hp is about 298 kW.

All horsepower conversions