Convert power instantly — type a value, pick your units, and every other common unit updates live below. 100% free, runs entirely in your browser, no sign-up.
Every unit below updates live from the value you enter in the "From" field above.
Power is energy per unit time, which is why its base unit (the watt) is defined as one joule per second. Horsepower predates the watt by a century — James Watt coined it to market steam engines by comparing them to actual horses — and this converter uses the standard "mechanical horsepower" (745.7 W); Europe's metric horsepower is very slightly different and not used here to keep the unit list simple.
Yes. It's completely free with no sign-up, and every conversion runs locally in your browser via JavaScript — the numbers you type are never sent to our servers.
Each unit uses its standard, internationally defined conversion factor, calculated in full precision and only rounded for display. Results are accurate to at least 6 significant figures.
This page intentionally covers the most commonly used power units rather than an exhaustive engineering list. Use the suggestion button in the bottom-right corner of any page to request a unit and we'll consider adding it.
Tell us what to improve or which tool to add next.
