Propane vs. oil heat cost depends on local fuel prices, furnace efficiency, and how much heat a home needs. For a home requiring about 80 million BTUs of delivered heat each year, fuel alone commonly costs $1,800-$3,300 with propane or $2,000-$3,200 with heating oil.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Propane fuel per gallon | $2.00 | $2.75 | $3.50 | Price varies by region, delivery, and contract |
| Heating oil per gallon | $3.00 | $3.75 | $4.50 | Seasonal and local supply affect price |
| Annual propane fuel | $1,800 | $2,500 | $3,300 | About 80 million delivered BTUs; 95% efficiency |
| Annual oil fuel | $2,000 | $2,550 | $3,200 | About 80 million delivered BTUs; 85% efficiency |
Assumptions: Typical U.S. delivered fuel ranges and equipment efficiencies; actual quotes and usage vary.
Annual propane and oil bills for the same heat demand
For a fair comparison, estimate fuel needed to deliver the same amount of heat rather than comparing gallons directly. A gallon of heating oil contains about 138,500 BTUs, while a gallon of propane contains about 91,500 BTUs. Furnaces convert only part of that energy into usable household heat.
At the example fuel prices, neither fuel is automatically cheaper; the local price per useful BTU decides. At $2.75 per propane gallon and 95% efficiency, propane costs roughly $31.60 per million delivered BTUs. At $3.75 per oil gallon and 85% efficiency, oil costs about $31.90 per million delivered BTUs. These estimates exclude equipment and service costs.
Assumptions: 80 million delivered BTUs per year; propane furnace efficiency 95%; oil furnace efficiency 85%.
What fuel, labor, and equipment add to the quote
The annual fuel estimate is only one part of the heating budget. A home already equipped for one fuel avoids conversion expenses, while switching systems can require a tank, piping, venting, or burner work. The table separates common costs from yearly fuel charges.
| Cost item | Propane range | Oil range | Typical scope |
|---|---|---|---|
| Fuel per gallon | $2.00-$3.50 | $3.00-$4.50 | Delivered residential fuel |
| Annual fuel for 80 million delivered BTUs | $1,800-$3,300 | $2,000-$3,200 | Depends on efficiency and price |
| Annual tune-up | $100-$250 | $150-$300 | Inspection and routine service |
| New furnace installation | $3,500-$8,000 | $4,000-$9,000 | Equipment and standard installation |
| Tank or conversion work | $500-$3,000 | $500-$2,500 | May rise with excavation or code work |
Compare installed costs separately from fuel prices when evaluating a change of system. Existing tanks, access, venting, and local code requirements can move installation bids substantially.
How furnace efficiency and home size change gallons
Use the calculation below to estimate annual gallons from the home’s delivered heat requirement. A contractor or past fuel records can help estimate annual BTUs; degree days, insulation, thermostat settings, and hot-water use also affect the total.
Gallons = annual delivered BTUs ÷ (fuel BTUs per gallon × furnace efficiency). For 80 million delivered BTUs, a 95%-efficient propane furnace uses about 920 gallons; an 85%-efficient oil furnace uses about 680 gallons. The lower oil gallon count does not necessarily mean a lower bill because the fuels have different energy content and prices.
Assumptions: Propane at 91,500 BTUs per gallon; oil at 138,500 BTUs per gallon; efficiency entered as a decimal.
Efficiency thresholds can change the comparison: replacing an 80%-efficient oil furnace with a 95%-efficient unit reduces required fuel for the same heat by about 16%. Likewise, a 90%-efficient propane system uses about 6% more fuel than a 95%-efficient one.
Why regional propane and oil prices shift the result
Fuel rates differ by delivery territory and season. Propane is common in rural areas without natural-gas service, but remote delivery routes and small orders can raise its delivered price. Heating oil is concentrated in the Northeast and Mid-Atlantic, where competition, storage, and winter demand influence quotes.
A 10% change in the delivered price usually changes the fuel portion of the annual bill by roughly 10%. Compare the complete delivered rate, including minimum delivery fees or tank charges, rather than a posted commodity price. A supplier’s payment plan can smooth monthly spending but does not necessarily lower the total.
Equipment age, tune-ups, and conversion costs
Oil systems need burner cleaning and nozzle or filter service; propane systems also need combustion checks and safety inspections. Typical annual service costs are about $100-$250 for propane and $150-$300 for oil, though emergency calls may cost more. Old or poorly maintained equipment can consume more fuel than its rated efficiency suggests.
Replacing a working furnace solely to chase a lower fuel price may take years to pay back. Add the new equipment, installation, tank work, and financing costs to the projected savings before deciding. A quote should state equipment efficiency, included parts, permits, warranty, and whether removal is included.
Three sample bills for different household heat needs
The following examples use the table’s average prices: propane at $2.75 per gallon and oil at $3.75. They compare fuel only, assuming 95% propane and 85% oil equipment efficiency; service, taxes, and equipment costs are not included.
| Delivered heat need | Propane gallons and cost | Oil gallons and cost | Estimated difference |
|---|---|---|---|
| 50 million BTUs | About 575 gal; $1,580 | About 425 gal; $1,595 | Near parity |
| 80 million BTUs | About 920 gal; $2,530 | About 680 gal; $2,550 | Near parity |
| 120 million BTUs | About 1,380 gal; $3,795 | About 1,020 gal; $3,825 | Near parity |
Assumptions: Rounded gallon estimates; costs are gallons multiplied by the stated sample fuel prices.
Ways to lower the annual propane or oil cost
Reduce the amount of heat required before changing fuels. Sealing drafts, improving attic insulation, and using a programmable thermostat can cut demand; results depend on the home’s starting condition. Keep equipment maintained so a dirty burner or misadjusted system does not waste fuel.
Compare suppliers using delivered price per gallon and fees, then compare cost per million useful BTUs. Ask about fixed-price plans, minimum orders, tank rental, and early-termination charges. For conversion projects, get itemized bids for the furnace, tank, labor, permits, and disposal, and compare them with the remaining life and repair cost of the existing system.
To calculate useful-BTU cost, divide the price per gallon by the product of BTUs per gallon and furnace efficiency, then multiply by one million. For example, $2.75 propane ÷ (91,500 × 0.95) × 1,000,000 is about $31.60 per million useful BTUs. Recalculate with local quotes and the actual equipment efficiency for a more meaningful comparison.