Power Unit Converter
How it works
Every unit here is turned into watts first — multiplying by the entered unit's own factor — and then divided back out by each of the five units' factors. One factor per unit rather than one formula per pair, and the five answers cannot disagree with each other.
Mechanical horsepower and metric horsepower get separate rows on purpose: they are two different units (745.7 W and 735.5 W respectively) that both happen to be called "horsepower," and folding them into one factor would quietly pick a side.
Frequently asked questions
What is the difference between mechanical and metric horsepower?
They are two separately defined units that happen to share an English name. Mechanical (imperial) horsepower is 745.7 watts, defined from foot-pounds per minute; metric horsepower — also written PS, CV or pk — is 735.5 watts, defined from kilogram-force metres per second. The gap is small, about 1.3%, but real: a car spec sheet from the US typically quotes mechanical horsepower, while one from much of Europe quotes metric horsepower, and mixing them up understates or overstates the true output.
What is BTU per hour commonly used for?
It's a power rating, distinct from the plain BTU used for a one-time amount of heat energy. Air conditioners, furnaces, space heaters and other heating or cooling equipment — especially in the US — are commonly rated in BTU/h to describe how fast they move heat.
How do watts and kilowatts relate to horsepower in practice?
This is mainly a translation problem: an engine or motor has one true power output, but different countries' spec sheets describe it in different units. Converting a car or motor's rating from kilowatts to horsepower — or checking whether a listed horsepower figure is the mechanical or metric kind — is the everyday reason to reach for this table rather than a single hard-coded factor.