# Horsepower Conversion

The horsepower is a unit used to measure power. Use one of the conversion calculators below to convert to another unit of measure, or read on to learn more about horsepower.

## Horsepower Conversion Calculators

Choose a unit of power to convert to.

**SI Units**

**US Customary & Imperial Units**

**Other Units**

**Related Calculators**

## Horsepower Definition and Usage

The term horsepower was adopted by Scottish inventor James Watt to measure the power output of his steam engine and to compare that power with that of horses horses.^{[1]} Horsepower were later used to measure the power output of piston and turbine engines and electrical motors.

There are now several different types of horsepower, including mechanical, electrical, metric, boiler, brake, and indicated, and they all have different applications in industry. Mechanical and electric are the most commonly used types.

### Mechanical Horsepower

Mechanical horsepower is often used to measure the output of engines and motors in North America. One mechanical horsepower is equal to 745.69987158227022 watts.

The mechanical horsepower is a US customary and imperial unit of power. Mechanical horsepower can be abbreviated as *hp(I)*, for example 1 mechanical horsepower can be written as 1 hp(I).

### Electric Horsepower

Electric horsepower is used to measure the output of electric motors and other electrical machines in the US. One electric horsepower is equal to exactly 746 watts.

The electric horsepower is a US customary and imperial unit of power. Electric horsepower can be abbreviated as *hp(E)*, for example 1 electric horsepower can be written as 1 hp(E).

### Metric Horsepower

One metric horsepower is the power needed to one metric horsepower as the lift a 75 kilogram mass at at one meter per second.^{[2]} One metric horsepower is equal to 735.49875 watts.

The metric horsepower is a non-SI metric unit for power. Metric horsepower can be abbreviated as *hp(M)*, and are also sometimes abbreviated as *PS*, *cv*, *hk*, *pk*, *ks*, or *ch*. For example, 1 metric horsepower can be written as 1 hp(M), 1 PS, 1 cv, 1 hk, 1 pk, 1 ks, or 1 ch.

### Boiler Horsepower

Boiler horsepower is used to measure the power of a boiler to generate steam.
One boiler horsepower is equal to the power needed to evaporate 34.5 pounds in one hour.^{[3]}

Boiler horsepower can be abbreviated as *hp(S)*, for example 1 boiler horsepower can be written as 1 hp(S).

Try our engine horsepower calculator to calculate the power of a motor.

## Horsepower Measurement Conversion Table

horsepower | watts | microwatts | milliwatts | kilowatts | megawatts | btu per hour | kilocalories per hour |
---|---|---|---|---|---|---|---|

1 hp | 745.699872 W | 745,699,872 µW | 745,700 mW | 0.7457 kW | 0.000746 MW | 2,544 Btu/h | 641.615691 kcal/h |

2 hp | 1,491 W | 1,491,399,743 µW | 1,491,400 mW | 1.4914 kW | 0.001491 MW | 5,089 Btu/h | 1,283 kcal/h |

3 hp | 2,237 W | 2,237,099,615 µW | 2,237,100 mW | 2.2371 kW | 0.002237 MW | 7,633 Btu/h | 1,925 kcal/h |

4 hp | 2,983 W | 2,982,799,486 µW | 2,982,799 mW | 2.982799 kW | 0.002983 MW | 10,178 Btu/h | 2,566 kcal/h |

5 hp | 3,728 W | 3,728,499,358 µW | 3,728,499 mW | 3.728499 kW | 0.003728 MW | 12,722 Btu/h | 3,208 kcal/h |

6 hp | 4,474 W | 4,474,199,229 µW | 4,474,199 mW | 4.474199 kW | 0.004474 MW | 15,267 Btu/h | 3,850 kcal/h |

7 hp | 5,220 W | 5,219,899,101 µW | 5,219,899 mW | 5.219899 kW | 0.00522 MW | 17,811 Btu/h | 4,491 kcal/h |

8 hp | 5,966 W | 5,965,598,973 µW | 5,965,599 mW | 5.965599 kW | 0.005966 MW | 20,355 Btu/h | 5,133 kcal/h |

9 hp | 6,711 W | 6,711,298,844 µW | 6,711,299 mW | 6.711299 kW | 0.006711 MW | 22,900 Btu/h | 5,775 kcal/h |

10 hp | 7,457 W | 7,456,998,716 µW | 7,456,999 mW | 7.456999 kW | 0.007457 MW | 25,444 Btu/h | 6,416 kcal/h |

11 hp | 8,203 W | 8,202,698,587 µW | 8,202,699 mW | 8.202699 kW | 0.008203 MW | 27,989 Btu/h | 7,058 kcal/h |

12 hp | 8,948 W | 8,948,398,459 µW | 8,948,398 mW | 8.948398 kW | 0.008948 MW | 30,533 Btu/h | 7,699 kcal/h |

13 hp | 9,694 W | 9,694,098,331 µW | 9,694,098 mW | 9.694098 kW | 0.009694 MW | 33,078 Btu/h | 8,341 kcal/h |

14 hp | 10,440 W | 10,439,798,202 µW | 10,439,798 mW | 10.439798 kW | 0.01044 MW | 35,622 Btu/h | 8,983 kcal/h |

15 hp | 11,185 W | 11,185,498,074 µW | 11,185,498 mW | 11.185498 kW | 0.011185 MW | 38,167 Btu/h | 9,624 kcal/h |

16 hp | 11,931 W | 11,931,197,945 µW | 11,931,198 mW | 11.931198 kW | 0.011931 MW | 40,711 Btu/h | 10,266 kcal/h |

17 hp | 12,677 W | 12,676,897,817 µW | 12,676,898 mW | 12.676898 kW | 0.012677 MW | 43,255 Btu/h | 10,907 kcal/h |

18 hp | 13,423 W | 13,422,597,688 µW | 13,422,598 mW | 13.422598 kW | 0.013423 MW | 45,800 Btu/h | 11,549 kcal/h |

19 hp | 14,168 W | 14,168,297,560 µW | 14,168,298 mW | 14.168298 kW | 0.014168 MW | 48,344 Btu/h | 12,191 kcal/h |

20 hp | 14,914 W | 14,913,997,432 µW | 14,913,997 mW | 14.913997 kW | 0.014914 MW | 50,889 Btu/h | 12,832 kcal/h |

## References

- Encyclopædia Britannica, Horsepower, https://www.britannica.com/science/horsepower
- Merriam-Webster, metric horsepower, https://www.merriam-webster.com/dictionary/metric%20horsepower
- Wikipedia, Horsepower, https://en.wikipedia.org/wiki/Horsepower

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