1 cubic foot = 1050 Btu
Therm = 100,000 Btu
Ccf = 100 cubic foot, or 1 therm
Mcf = 1000 cubic feet = 10.20 therms
MMcf = 1 million cubic feet
Bcf = 1 billion cubic feet
Decatherm (Dth) = 10 therms = 1 million Btu
Mmbtu = 1 million but = 10 therms