Convert power between watts, kilowatts, megawatts, horsepower, and BTU per hour. Power is the rate energy is used, and it turns up in car engines, appliances, solar panels, and air conditioning, usually quoted in whatever unit a given industry prefers. Horsepower is especially tricky because there are two common definitions, metric and mechanical, and they differ slightly, so this converter includes both with their exact values. Pick the unit you have and the one you want, type a value, and the result updates live as you type. Whether you are comparing engine outputs or sizing an appliance, the answer is immediate. It all runs in your browser, so the tool is fast, keeps your figures private, and works offline after loading.