How many watts are in one horsepower?

One mechanical (imperial) horsepower equals approximately 745.7 watts. One metric horsepower (PS) equals approximately 735.5 watts. The difference matters when comparing European and American vehicle specifications.

What is the difference between mechanical and metric horsepower?

Mechanical (imperial) horsepower equals 745.7 watts and is used in the US and UK. Metric horsepower (PS/CV/pk) equals 735.5 watts and is used in Europe and Asia. The difference is about 1.4%, so 100 mechanical hp = 101.4 metric hp.

How do I convert kilowatts to horsepower?

Multiply kilowatts by 1.341 to get mechanical horsepower, or multiply by 1.3596 for metric horsepower. For example, a 100 kW electric motor produces about 134.1 mechanical horsepower.

How to Convert Watts to Horsepower - Formula, Examples & Chart

The Watts to Horsepower Formula

There are two common horsepower standards. Choose the one appropriate for your context:

Mechanical HP = Watts ÷ 745.7

Metric HP (PS) = Watts ÷ 735.5

Mechanical (imperial) horsepower is standard in the US and UK. Metric horsepower, known as PS (Pferdestärke) in German, CV in French and Spanish, or pk in Dutch, is used across continental Europe and Asia.

Step-by-Step Examples

Example 1: A 1,500W Electric Motor

Calculation: 1,500 ÷ 745.7 = 2.01 mechanical hp.
Result: A 1,500W motor produces approximately 2 horsepower.

Example 2: A 150 kW Electric Car Motor

Calculation: 150,000 ÷ 745.7 = 201.2 mechanical hp.
Result: 150 kW = approximately 201 horsepower.

Example 3: A 746W Motor (Exactly 1 HP)

Calculation: 746 ÷ 745.7 = 1.0004 hp.
Result: 746W is almost exactly 1 horsepower, which is why electric motors are often rated in multiples of 746W.

Power Conversion Reference Table

Watts	Kilowatts	Mechanical HP	Metric HP (PS)
100	0.1	0.13	0.14
500	0.5	0.67	0.68
746	0.746	1.00	1.01
1,000	1.0	1.34	1.36
5,000	5.0	6.71	6.80
10,000	10.0	13.41	13.60
50,000	50.0	67.05	67.98
100,000	100.0	134.10	135.96
200,000	200.0	268.20	271.93

Real-World Applications

Electric Vehicles

EV manufacturers often list motor output in kilowatts, but consumers are used to thinking in horsepower. A Tesla Model 3 Performance with a 358 kW motor produces 480 hp, giving context to its performance capabilities.

Home Appliances and Tools

Vacuum cleaners, blenders, and power tools are rated in watts, while shop equipment like air compressors and table saws often use horsepower. A 1,200W shop vacuum is roughly 1.6 hp.

Industrial Motors

Electric motors for industrial use are commonly specified in both watts (or kW) and horsepower depending on the market. Accurate conversion ensures proper motor selection for the required load.

Quick Estimation

For a fast mental conversion from watts to horsepower, divide by 750. This is within 0.6% of the exact value and much easier to compute. For kilowatts to horsepower, multiply by 1.34. Use our power converter for precise calculations.