The following formulas allow you to compare the cost of different fuels based on their heat equivalents and typical heating system efficiency.
| Fuel | Heat equivalent | Burner Efficiency | Cost - $/Million Btu |
| Fuel oil | 138,500 Btu/gallon | 70% | $/MBtu = $/gal x 10.3 |
| Fuel oil | 138,500 Btu/gallon | 75% | $/MBtu = $/gal x 9.6 |
| Waste oil | 125,000 Btu/gallon | 70% | $/MBtu = $/gal x 11.4 |
| Natural gas | 100,000 Btu/therm | 75% | $/MBtu = $/therm x 13.3 |
| Natural gas | 100,000 Btu/therm | 90% | $/MBtu = $/therm x 12.5 |
| Natural gas | 103,000 Btu/ccf | 90% | $/MBtu = $/ccf x10.8 |
| Propane | 92,500 Btu/gallon | 75% | $/MBtu = $/gal x 14.4 |
| Propane | 92,500 Btu/gallon | 90% | $/MBtu = $/gal x 12.0 |
| Hard coal | 25,000,000 Btu/ton | 60% | $/MBtu = $/ton ÷ 15.0 |
| Hard coal | 25,000,000 Btu/ton | 75% | $/MBtu = $/ton ÷ 18.7 |
| Hardwood | 20,000,000 Btu/cord | 60% | $/MBtu = $/cord ÷ 12 |
| Softwoods | 12,000,000 Btu/cord | 60% | $/MBTu = $/cord ÷ 7.2 |
| Wood Pellets | 8,200 Btu/lb | 80% | $/MBtu = $/ton ÷ 13.1 |
| Wood chips | |||
| Green (45% m.c.) | 4,500 Btu/lb | 75% | $/MBtu = $/ton ÷ 6.75 |
| Green (45% m.c.) | 2,000,000 Btu/cu yd | 75% | $/MBtu = $/cu yd ÷ 1.5 |
| Green(50% m.c.) 4,000 Btu/lb | 50% | $/MBtu = $/ton ÷ 4.0 | |
| Dry (10% m.c.) 7,400 Btu/lb | 60% | $/MBtu = $/ton ÷ 8.8 | |
| Corn | 8,200 Btu/lb | 80% | $/MBtu = $/ton ÷ 13.1 |
| Biofuels | |||
| Vegetable oil | 120,000 Btu/gal | 70% | $/MBtu = $/gal x 11.9 |
| Electricity | 3,412 Btu/kilowatt-hour | 100% | $/MBtu = $/kw-hr x 293 |
John W. Bartok, Jr., Extension Professor Emeritus & Agricultural Engineer, Department of Natural Resources and the Environment, University of Connecticut, Storrs CT – Updated 2013.