Power Converter

Frequently asked questions

How many watts are in one horsepower?

One mechanical horsepower equals about 745.7 watts, so a 100 hp engine is roughly 74.6 kW. Air-conditioner capacity is often quoted in BTU per hour, where 1 watt equals 3.412 BTU/h and a 1 kW unit is about 3412 BTU/h.

What is the difference between mechanical horsepower and metric horsepower?

Mechanical horsepower (used in the US) is exactly 550 foot-pounds per second, which equals about 745.7 watts. Metric horsepower (used in Europe) is defined as 75 kilogram-force-metres per second, which equals about 735.5 watts. The difference is about 1.4%, which matters when comparing vehicle specifications across regions.

How do I convert kilowatts to BTU per hour for an air conditioner?

Multiply the kilowatt value by 3,412 to get BTU per hour. A common 3.5 kW split air conditioner is therefore about 11,940 BTU/h, which is often marketed as a 12,000 BTU or 1-ton unit. This converter does that calculation automatically in the reference table.

Why does the converter use six decimal places?

Power conversions involving horsepower and BTU/h produce irrational decimal strings because the underlying conversion factors are not round numbers. Six decimal places give enough precision for engineering work without displaying a misleadingly long string of digits.