British Thermal Unit - Conversions

Conversions

One Btu is approximately:

• 1.054 to 1.060 kJ (kilojoules)
• 0.293071 W·h (watt hours)
• 252 to 253 cal (calories, or "little calories")
• 0.25 kcal (kilocalories, "large calories," or "food calories")
• 25 031 to 25 160 ft·pdl (foot-poundal)
• 778 to 782 ft·lbf (foot-pounds-force)

Other conversions:

• In natural gas, by convention 1 MMBtu (1 million Btu, sometimes written "MMBtu") = 1.054615 GJ. Conversely, 1 gigajoule is equivalent to 26.8 m3 of natural gas at defined temperature and pressure. So, 1 MMBtu = 28.263682 m3 of natural gas at defined temperature and pressure, that is 998.12 ft3 .
• 1 standard cubic foot of natural gas yields ≈ 1030 Btu (between 1010 Btu and 1070 Btu, depending on quality, when burned)
• As a coarse approximation, 1000 ft3 of natural gas ≈ 1 MMBtu ≈ 1 GJ