Appendix G
Unit Conversion Factors and Energy Ratings
CONVERSION FACTORS
1 Btu [British thermal unit] = 1.055 kJ [kilojoules] = 252 cal [calories]
1 cal = 0.003967 Btu = 4.184 J
1 quad [quadrillion Btu] = 1015 Btu
1 Btu/lb = 0.556 kcal/kg
ENERGY RATINGS
1 tce [tonne of coal equivalent] = 29.308 GJ = 27.778 million Btu
1 toe [tonne of oil equivalent] = 41.868 GJ = 39.683 million Btu
“Coal equivalent” coal = 7,000 kcal/kg
High-rank coal = 7,000 kcal/kg
Low-rank coal = 3,500 kcal/kg
Lignite = 2,700 kcal/kg
1 ton lignite = 0.3 to 0.63 tce (average 0.38)
1 ton subbituminous = 0.78 tce