Horsepower to Watts Converter

Convert mechanical (imperial) horsepower to watts. 1 hp = 745.7 W.

Inputs

Result

Loading calculator…
—

General calculation reads

Amazon affiliate
How Not to Be Wrong
Jordan Ellenberg - math thinking
Shop on Amazon
The Joy of X
Steven Strogatz - accessible math
Shop on Amazon
Scientific calculator (Casio fx-991EX)
Shop on Amazon

As an Amazon Associate we may earn from qualifying purchases. This does not add cost for you.

How to use this calculator

  • Enter horsepower.
  • Pick HP type (mechanical for US cars, metric for Euro cars, electrical for motor specs).
  • Read watts and kW.

About this calculator

"Horsepower" actually has three definitions used in different contexts. Mechanical (or imperial) is 745.7 W — used for cars in the US. Metric (PS, Pferdestärke, used in Europe) is 735.5 W. Electrical is exactly 746 W — used by motor manufacturers. The differences are small (<2%) but matter for precise conversions.

Frequently asked

Why are there multiple horsepower units?+
Historical accident. Watt defined his 1 hp ≈ 33,000 ft-lbf/min (mechanical). Metric horsepower came from continental Europe at 75 m·kgf/s. Electrical horsepower was rounded for motor specifications.
Which is used for cars?+
US: mechanical hp. Europe: metric (often called "PS" or "BHP"). Watch for "BHP" specifically — same as mechanical hp.
Is "horsepower" a force or a power?+
Power — energy per time. Watt is the SI unit (1 J/s).
What about "boiler horsepower"?+
Yet another definition (9809 W) used in steam-heating systems. Different from any of the three above.
How accurate is the 1 hp ≈ 0.75 kW shortcut?+
Within 1.5% — fine for back-of-envelope. For precise conversion, use the calculator.

Related calculators

Watts to Horsepower Converter
Convert watts to horsepower. 1000 W ≈ 1.341 hp (mechanical).
BTU to kWh Converter
Convert British thermal units to kilowatt-hours. 1 BTU ≈ 0.000293 kWh.
kWh to BTU Converter
Convert kilowatt-hours to BTU. 1 kWh = 3,412 BTU.
Calorie to Joule Converter
1 cal (thermochemical) = 4.184 J. 1 kcal (food calorie) = 4,184 J.
Electrical Power Calculator
P = IV — compute power from voltage and current, or from voltage and resistance, or current and resistance.
Ohm's Law Calculator (Extended)
V = IR, P = IV = I²R = V²/R. Pick which two values you know and solve for the others.

More tools you might like

Hand-picked tools that pair well with this one — same audience, same intent.

Watts to Horsepower Converter
Calc

Convert watts to horsepower. 1000 W ≈ 1.341 hp (mechanical).

BTU to kWh Converter
Calc

Convert British thermal units to kilowatt-hours. 1 BTU ≈ 0.000293 kWh.

kWh to BTU Converter
Calc

Convert kilowatt-hours to BTU. 1 kWh = 3,412 BTU.

Calorie to Joule Converter
Calc

1 cal (thermochemical) = 4.184 J. 1 kcal (food calorie) = 4,184 J.

Ohm's Law Calculator (Extended)
Calc

V = IR, P = IV = I²R = V²/R. Pick which two values you know and solve for the others.

Currency Converter
Finance

Convert between 30 major world currencies using a snapshotted static rate table — clearly marked, not live.