Oil heat typically costs about $2,200-$3,100 per year in fuel for a typical U.S. home, while natural gas often costs $1,100-$1,800. The oil vs. gas heat price comparison depends on local fuel rates, equipment efficiency, home insulation, and whether switching systems requires a gas-line extension or other upgrades.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Annual oil fuel | $2,200 | $2,650 | $3,100 | About 680 gallons yearly |
| Annual natural gas fuel | $1,100 | $1,450 | $1,800 | About 90 therms yearly |
| New oil furnace | $5,000 | $7,500 | $10,000 | Installed, standard replacement |
| New gas furnace | $4,000 | $6,500 | $9,000 | Installed, existing gas connection |
| Oil-to-gas conversion | $8,000 | $12,000 | $18,000 | May include gas-line work |
Assumptions: Typical 1,800-2,200-square-foot home, standard equipment, normal access, and regional fuel-rate variation.
Typical annual oil and gas heating prices
For a home needing roughly 80 million BTU of delivered heat each winter, oil commonly runs about $2,200-$3,100 in fuel. This estimate assumes approximately 680 gallons at $3.25-$4.50 per gallon and an oil furnace near 85% efficiency. Actual use varies with weather and insulation.
Natural gas for similar heat demand may cost about $1,100-$1,800 per year, assuming roughly 90 therms at $1.20-$2.00 per therm and a 90% efficient furnace. Monthly customer charges can add roughly $10-$35, depending on the utility. Gas often has the lower yearly fuel bill where pipeline service is available at ordinary residential rates.
What furnace, fuel, and conversion work add to the quote
A furnace-only replacement is not the same expense as switching fuels. An oil-to-gas project can require a gas connection, venting changes, tank removal, and permits. The table shows common installed ranges; unusual access or major code work can raise them.
| Quote item | Oil system | Gas system | Conversion range |
|---|---|---|---|
| Furnace and installation | $5,000-$10,000 | $4,000-$9,000 | $4,000-$8,000 |
| Fuel tank work | $500-$2,500 | Not applicable | $500-$3,000 |
| Gas piping and meter work | Not applicable | $300-$1,500 | $1,000-$5,000 |
| Venting, permits, and disposal | $300-$1,500 | $300-$1,200 | $800-$2,500 |
Labor commonly accounts for $1,500-$4,000 of a furnace replacement, with installation taking 8-16 hours for a two-person crew. Tank excavation, long pipe runs, or chimney-liner work may be quoted separately. Ask whether the estimate includes tank removal, permits, venting, and start-up testing.
How furnace efficiency and home size change fuel use
Annual fuel costs rise with heat demand, not just furnace size. A drafty 2,500-square-foot house can use substantially more fuel than a tight 1,500-square-foot home, even with similar equipment. A contractor should size the furnace using a heat-loss calculation rather than square footage alone.
Efficiency also affects the comparison. Replacing an older 70%-efficient furnace with a 95%-efficient model can reduce the fuel needed for the same heat output, although savings depend on the old system’s condition and local rates. Oil furnaces commonly fall around 80%-87% AFUE; gas models are available from roughly 80% to 98%. Compare delivered heat cost, not the fuel price per gallon against the price per therm.
How to lower the oil-to-gas conversion price
Keep the project scope clear: request separate prices for the furnace, gas connection, tank removal, venting, and electrical or duct changes. If the oil tank is above ground and accessible, removal may cost less than an underground tank requiring excavation and soil testing.
Compare at least three written quotes with matching equipment efficiency and warranty terms. Avoid paying for a premium furnace unless its added efficiency is likely to offset the higher purchase price under local utility rates. Sealing air leaks and improving attic insulation can reduce either fuel bill, sometimes making a replacement less urgent. Repair may be the cheaper short-term choice when the existing furnace is safe, serviceable, and not near end of life.
Regional fuel rates shift the oil-versus-gas break-even point
Oil heat is concentrated in parts of the Northeast, where delivery access and seasonal demand can affect per-gallon quotes. In areas with established gas pipelines, gas service may be cheaper to operate, but extending a main or installing a long private gas line can erase several years of fuel savings. Rural homes may also face limited fuel choices and higher delivery charges.
Local prices can differ by 10%-30% or more from broad estimates, especially during cold snaps or when a home needs an emergency delivery. Request a current delivered oil price and the utility’s full gas rate, including customer charges and delivery fees. A low fuel rate is not a savings if conversion costs are unusually high.
Three heating quotes for common home scenarios
For a 1,600-square-foot home with an existing oil furnace connection, a standard oil replacement might total $6,200-$8,000, including 10-12 labor hours. A gas-furnace replacement in a home already connected to gas may run $5,000-$7,500, including similar labor.
For a 2,000-square-foot home switching from oil to gas, an example quote could include a $6,500 furnace, $2,500 gas piping, $1,200 tank removal, and $900 permits and venting, for about $11,100 total. A 2,800-square-foot home with a long gas-line run and underground tank could reach $15,000-$18,000. These examples assume standard ductwork and no major structural repairs.
When lower gas bills repay a furnace conversion
If gas saves $900-$1,500 annually and conversion costs $8,000-$18,000, simple payback ranges from about 5 to 20 years. The calculation excludes financing, maintenance differences, and future changes in fuel prices. A high-cost line extension or a home with low annual heating use lengthens payback.
Oil systems need periodic burner service and filter changes; annual tune-ups commonly cost $150-$300. Gas furnace maintenance often costs $100-$250 per year. Add these expenses to the fuel comparison, but do not assume that one system will never need repairs. Use local fuel quotes and a fully itemized conversion estimate to determine whether the projected savings justify the upfront price.