How to Determine BTU by Horsepower

Horsepower and the British Thermal Unit (BTU) are both measurements of energy. Each of these units quantifies heat or energy in general, but in different ways. With the proper formulas, however, you can convert horsepower into BTU and vice versa. The British Thermal Unit is most accurately defined as the energy required to raise the temperature of 16 ounces of water by 1 degree F. Horsepower is a measure of power, and 1 horsepower is equivalent to 33,000 pound-feet per minute of work.

Converting from Horsepower to BTU

• 1

  Find the horsepower given for your machine. This information is usually available from an owner's manual or the manufacturer's website. With vehicles, check for the exact year and engine type because the horsepower can vary a lot among different models.

• 2
  Boiler horsepower (BHP) is a separate unit that measures the amount of steam moved per hour. teekocher image by Dron from Fotolia.com

  Multiply a boiler's horsepower by 33,479 to find out BTU per hour. BTU-hours are the standard unit when something refers to just "BTU."

• 3

  Multiply the horsepower of all other machines by 2546.4 to find BTU-hours. If you seek BTU-minutes, divide the BTU-hour figure by 60.

Converting from BTU to Horsepower

• 1

  Find your appliance or machine's BTU. This figure is listed in owner's manuals, on manufacturer websites and frequently on a sticker on the appliance itself.

• 2

  Multiply the BTU by 0.0003931 to find the answer in horsepower-hours.

• 3

  Multiply a BTU-minute figure by 0.02356 to find horsepower.