Which delivers more heat per gallon, heating oil or propane?

Heating oil delivers more heat per gallon. A gallon of #2 fuel oil contains about 138,500 BTUs, while a gallon of propane contains about 91,500 BTUs. That means a home burning heating oil consumes fewer gallons per heating season than the same home burning propane, even though propane equipment is often more efficient on a percentage basis.

Is propane cheaper than heating oil?

It depends on the regional fuel market and the time of year. Propane is often quoted at a lower price per gallon than heating oil, but because each gallon of propane carries about a third less energy, the cost per delivered BTU is what matters. Compare your local propane and heating-oil price per gallon, divide each by its BTU content (91,500 for propane, 138,500 for heating oil), and use the cost per million BTU to compare apples to apples.

Can I use the same furnace for propane and heating oil?

No. Propane furnaces and heating-oil furnaces use different burners, different fuel lines, and different ignition systems. Switching between fuels means replacing the appliance or, in some cases, swapping a dual-fuel-rated burner assembly. Plan on a full furnace or boiler replacement when converting between the two.

What size propane tank do I need for whole-home heating?

Most whole-home propane heating setups in cold climates use a 500-gallon or 1,000-gallon above-ground tank. A 500-gallon tank holds about 400 usable gallons (tanks are filled to roughly 80%) and supports a typical 2,000–2,500 sqft home through most of a New England winter between deliveries. Larger or less-insulated homes step up to 1,000 gallons.

Is propane cleaner-burning than heating oil?

Propane combustion produces fewer particulates and lower sulfur emissions than #2 heating oil, and the EPA classifies propane as a clean alternative fuel under the 1990 Clean Air Act. Modern ultra-low-sulfur heating oil (ULSHO) and B20 biofuel blends have closed much of the gap, but propane still tends to leave less soot in the appliance and chimney.

Heating Oil vs Propane: Cost, BTUs, and Equipment Fit

Compare heating oil and propane head-to-head: BTUs per gallon, typical delivered price, equipment compatibility, tank ownership, and which fits which kind of home.

Heating oil and propane are the two dominant delivered fuels for homes without natural-gas service. They are sold the same way — by the gallon, delivered by truck, billed per fill-up — but the equipment, costs, and geographic fit are different enough that the choice usually comes down to what is already installed in the home.

How they stack up at a glance

Factor	Heating Oil (#2)	Propane (LP-Gas)
Energy per gallon	~138,500 BTU	~91,500 BTU
Typical equipment	Oil furnace or boiler	Gas furnace, boiler, or warm-air unit
Storage	Indoor or outdoor steel tank, owned	Above-ground or buried tank, often leased
Best fit	Older homes in the Northeast	Rural homes anywhere LP service runs
Other appliances served	Heat and hot water only	Heat, hot water, range, dryer, generator

Energy density and operating cost

The single biggest difference is energy density. A gallon of #2 heating oil packs about 138,500 BTUs; a gallon of propane packs about 91,500 BTUs. To compare prices fairly, convert both to dollars per million BTU:

Heating oil $/MMBTU = (price per gallon ÷ 138,500) × 1,000,000
Propane $/MMBTU = (price per gallon ÷ 91,500) × 1,000,000

A propane gallon at $3.00 and a heating-oil gallon at $4.00 work out to roughly $32.79/MMBTU and $28.88/MMBTU respectively — heating oil is actually the cheaper energy source even though its sticker price per gallon is higher.

Modern condensing propane furnaces hit AFUE ratings in the mid-90s, while a typical oil burner runs in the mid-80s, which narrows the gap. Equipment efficiency is the second number to plug in alongside the fuel price.

Equipment compatibility

Oil and propane equipment are not interchangeable. Oil burners atomize liquid fuel; propane burners mix vapor with combustion air through a gas valve. Switching fuels means replacing the appliance.

If you are remodeling or replacing a furnace anyway, that is the natural point to evaluate the switch. If your current oil-fired boiler still has a decade of service in it, the math rarely favors a forced conversion.

Tank ownership

Heating-oil tanks are almost always owned by the homeowner and filled by whichever supplier offers the best price that month. Propane tanks are more often leased from a single supplier, who is then the only company allowed to refill that tank. Owning your propane tank unlocks competitive bidding and is the lever that makes the propane market behave more like the heating-oil market.

Multi-fuel households

Many rural homes use both. A common setup is heating oil for the furnace and hot water (because the equipment was already there) and propane for the kitchen range, the clothes dryer, and a backup generator. Each fuel runs on its own tank and its own delivery cycle.

Which is right for your home?

Stay with what is installed unless you are replacing the appliance
anyway. Conversion costs usually exceed the per-BTU savings.
Pick propane for new construction in rural areas, for homes that
also want gas appliances, and where heating-oil dealers are scarce.
Pick heating oil in dense Northeastern markets where competition
among oil dealers keeps prices low, and where the home already has an
oil-fired boiler with serviceable life left.

Use the directory to find local propane dealers and heating-oil dealers serving your ZIP, then run the cost-per-MMBTU math against your own current bill before making the call.

Find dealers in your ZIP

Enter your ZIP to see if a local fuel dealer in our directory serves your area.

Frequently asked questions

Which delivers more heat per gallon, heating oil or propane?: Heating oil delivers more heat per gallon. A gallon of #2 fuel oil contains about 138,500 BTUs, while a gallon of propane contains about 91,500 BTUs. That means a home burning heating oil consumes fewer gallons per heating season than the same home burning propane, even though propane equipment is often more efficient on a percentage basis.
Is propane cheaper than heating oil?: It depends on the regional fuel market and the time of year. Propane is often quoted at a lower price per gallon than heating oil, but because each gallon of propane carries about a third less energy, the cost per delivered BTU is what matters. Compare your local propane and heating-oil price per gallon, divide each by its BTU content (91,500 for propane, 138,500 for heating oil), and use the cost per million BTU to compare apples to apples.
Can I use the same furnace for propane and heating oil?: No. Propane furnaces and heating-oil furnaces use different burners, different fuel lines, and different ignition systems. Switching between fuels means replacing the appliance or, in some cases, swapping a dual-fuel-rated burner assembly. Plan on a full furnace or boiler replacement when converting between the two.
What size propane tank do I need for whole-home heating?: Most whole-home propane heating setups in cold climates use a 500-gallon or 1,000-gallon above-ground tank. A 500-gallon tank holds about 400 usable gallons (tanks are filled to roughly 80%) and supports a typical 2,000–2,500 sqft home through most of a New England winter between deliveries. Larger or less-insulated homes step up to 1,000 gallons.
Is propane cleaner-burning than heating oil?: Propane combustion produces fewer particulates and lower sulfur emissions than #2 heating oil, and the EPA classifies propane as a clean alternative fuel under the 1990 Clean Air Act. Modern ultra-low-sulfur heating oil (ULSHO) and B20 biofuel blends have closed much of the gap, but propane still tends to leave less soot in the appliance and chimney.