How Many Watts in a Horsepower?

Quick Answer

There are approximately 745.7 watts in a mechanical horsepower.

1 horsepower ≈ 745.7 watts

Understanding the Conversion

One mechanical (imperial) horsepower equals approximately 745.7 watts or 0.7457 kilowatts. This unit was defined by James Watt to compare steam engine output to draft horses. Metric horsepower (PS) is slightly different at about 735.5 watts.

Formula

1 horsepower ≈ 745.7 watts

Common Examples

DescriptionValue
A 150 hp car engineAbout 111,855 watts (112 kW)
A 1 hp electric motorAbout 746 watts
A 300 hp sports carAbout 223,710 watts (224 kW)

Quick Reference Table

Use this table for quick conversions between horsepower and watts:

horsepowerwatts
1745.7
21,491.4
53,728.5
107,457
2518,642.5
5037,285
10074,570

Frequently Asked Questions

How Many Watts in a Horsepower?

There are approximately 745.7 watts in a mechanical horsepower. One mechanical (imperial) horsepower equals approximately 745.7 watts or 0.7457 kilowatts. This unit was defined by James Watt to compare steam engine output to draft horses. Metric horsepower (PS) is slightly different at about 735.5 watts.

What is the formula to convert horsepower to watts?

The formula is: 1 horsepower ≈ 745.7 watts. To convert, multiply the number of horsepowers by 745.7 to get the equivalent in watts.

How do I convert watts to horsepower?

To convert watts to horsepower, divide the number of watts by 745.7. For example, 3,728.5 watts equals 5 horsepowers.

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