Heating Oil vs Propane Calculator
| Oil \ propane per gallon | $2.20 | $2.60 | $3.00 | $3.40 | $3.80 |
|---|---|---|---|---|---|
| $3.50 | Oil | Propane | Propane | Propane | Propane |
| $4.00 | Oil | Oil | Propane | Propane | Propane |
| $4.50 | Oil | Oil | Propane | Propane | Propane |
| $5.00 | Oil | Oil | Oil | Propane | Propane |
| $5.50 | Oil | Oil | Oil | Oil | Propane |
Enter the two delivery prices and the calculator converts both into dollars per million BTU - the only fair way to compare fuels sold in different energy densities.
The gallon prices lie to each other: propane looks cheap per gallon and heats like it, because a gallon of propane carries about 91,500 BTU against roughly 138,500 for heating oil. The two-thirds rule falls out of that - propane has to cost less than about two-thirds of the oil price to heat for less - and the calculator prices your exact quotes instead of the rule.
How to use
- Use delivery quotes, not spot headlines - oil and propane both move week to week in heating season.
- Ignore equipment efficiency unless you know it differs; both fuels burn near 80 percent in standard equipment, so the BTU math carries the comparison.
- Read the crossover line: at your oil price, propane wins below the price the calculator prints. Updates live.
Frequently asked questions
Is propane cheaper than heating oil?
Per gallon, always; per BTU, only below the crossover - propane must beat about two-thirds of the oil price. At 4 dollar oil that is roughly 2.65 a gallon, and the calculator prints your exact line at your quotes.
Why does propane have less energy per gallon?
Energy density: propane weighs about 4.2 pounds a gallon where heating oil weighs about 7 - the oil gallon simply packs more carbon to burn. That is why the per-gallon price comparison flatters propane and the per-BTU comparison does not.
When does switching fuels actually pay?
Only when the equipment changes anyway: a furnace or boiler conversion runs thousands of dollars, so the per-year savings has to repay the switch - usually a decade or more at typical price gaps. Fuel switching is a buy-when-it-breaks decision, not a price-ticker decision.
Do oil and propane prices move together?
Loosely - both track crude oil, but propane is also a byproduct of natural gas processing, so mild winters and gas gluts can pull the two prices apart for whole seasons. That divergence is exactly when the crossover calculator earns its keep.
Which fuel is better for a backup generator or tank?
Propane stores indefinitely in a tank and feeds generators and cooktops; oil needs the furnace and degrades slowly over years. Households that want one fuel for heat plus backup tend to land on propane even at a small BTU premium.