Heating oil and propane are sold by the gallon, but a gallon of each holds a different amount of heat, so comparing the price per gallon is misleading. Heating oil contains about 137,381 Btu per gallon; propane contains about 91,452 Btu per gallon (U.S. Energy Information Administration conversion factors). It takes roughly 1.5 gallons of propane to produce the same heat as one gallon of heating oil.
This week's cost per million Btu
| Fuel | U.S. price per gallon | Btu per gallon | Cost per million Btu |
|---|---|---|---|
| Heating oil | $6.233 | 137,381 | $45.37 |
| Propane | $2.730 | 91,452 | $29.85 |
At this week's national averages, propane is about 34% cheaper per unit of heat. That figure moves every week, and prices in your own state can tell a different story — compare your state's figures on the heating oil and propane pages.
What the comparison leaves out
- Equipment efficiency. The figures above compare heat in the fuel. A modern high-efficiency furnace or boiler turns more of that heat into warmth for your home than an older one, whichever fuel it burns.
- Taxes and fees. Survey prices exclude taxes, and tank rental, delivery or minimum-order charges vary by supplier.
- Switching costs. Changing fuel usually means a new appliance and tank, so the running-cost difference has to pay that back over time.