Use this free horsepower calculator to convert between mechanical horsepower, metric horsepower, watts, and kilowatts.
150 horsepower
Mechanical horsepower, metric horsepower, electric horsepower, and boiler horsepower are different units. This tool reports common mechanical and metric values.
Recent horsepower conversions will appear here.
Power conversions run locally and use NIST-style conversion factors for common horsepower units.
Inputs and recent answers stay in this browser tab and are not sent to a server.
Convert horsepower to watts or kilowatts.
Convert kilowatts into mechanical horsepower.
Compare mechanical horsepower with metric horsepower.
Check power-unit labels on motors, tools, and engines.
111,854.985 W
134.1022 hp
73,549.88 W
Need a slower walkthrough, a related calculator, or the full library? These links keep you close to the task you started.
Plain-language answers about when to use the tool, what it does with your inputs, what to double-check, and how privacy works.
Use it when your task matches one of these common needs: Convert horsepower to watts or kilowatts. Convert kilowatts into mechanical horsepower. It works best when you already know the value, source unit, target unit, format, or mode the page asks for.
In plain language: The calculator converts the starting unit to watts, then divides by 745.6999 for mechanical horsepower or 735.4988 for metric horsepower. The examples on the page are there so you can compare your inputs with a filled-out example before copying the answer.
Power value: the number printed on the label, spec sheet, motor plate, or example you want to convert. Starting unit: the unit your number already uses, such as mechanical horsepower, metric horsepower, watts, or kilowatts. Mechanical horsepower: the common hp unit used in many US engine and motor examples, equal to about 745.6999 watts. Metric horsepower: a slightly smaller horsepower unit, equal to about 735.4988 watts.
Read the output next to your original input. If the tool changes format, units, encoding, spacing, or capitalization, compare a small sample before copying the whole result into another app.
Horsepower units are not all the same. Confirm whether your label means mechanical, metric, electric, boiler, or another horsepower standard. Also check the source unit, target unit, format, decimal places, and selected mode because small input changes can change the result.
No. One mechanical horsepower is about 745.6999 watts. One metric horsepower is about 735.4988 watts. The difference is small, but it matters when you compare labels or spec sheets closely.
No. This page converts power units you already have. If you have torque and RPM, use the Engine Horsepower Calculator instead because it uses torque x RPM / 5252.1131.
Watts and kilowatts are standard power units on electrical and equipment labels. They make it easier to compare motors, tools, and engines even when one source lists hp and another lists kW.
No. The tool runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.