The British thermal unit (BTU or Btu) is a unit of heat; it is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.
One Btu is approximately:
- 054 to 1.060 kJ (kilojoules)
- 2931 W⋅h (watt hours)
- 252 to 253 cal (calories)
- 25 kcal (kilocalories)