Pick a species, enter what you pay and how much wood you get, and your stove’s efficiency. The calculator shows the cost per million Btu that reaches the room, cords per season, and the same figure for propane, heating oil, natural gas, electric resistance and a heat pump. It runs in your browser; nothing is stored.

Firewood cost calculator

1. Your firewood

Species

Air-dried heat per full cord (USU Extension).

Heat per full cord (million Btu)

Filled from the species; type over it for a mixed load.

Price you pay ($)

Volume you get for that price (cubic feet, stacked)

Full cord = 128 (4 × 4 × 8 ft). Measure a face cord or rick: length × height × log length.

Stove efficiency (%)

From the spec sheet (HHV). EPA: non-catalytic about 71%, catalytic about 78%.

Heat your home needs per season (million Btu, optional)

Example value. From past fuel use: gallons × Btu per gallon × furnace efficiency ÷ 1,000,000.

2. Other fuels (example prices: replace with yours)

Propane ($/gal)

Propane efficiency (%)

Heating oil ($/gal)

Oil efficiency (%)

Natural gas ($/therm)

Gas efficiency (%)

Electricity ($/kWh)

Default: U.S. average residential, EIA, July 2026.

Heat pump seasonal COP

Example; HSPF2 ÷ 3.412 is a rough seasonal COP.

Your results

Price per full-cord equivalent

Cost per million Btu in the wood

Cost per million Btu delivered to the room

Full cords per season

Firewood cost per season

Delivered cost per million Btu, other fuels

Propane

Heating oil

Natural gas

Electric resistance

Heat pump

How this is calculated

Delivered cost = (price × 128 ÷ cubic feet bought) ÷ million Btu per cord ÷ efficiency. Cords per season = heat needed ÷ (million Btu per cord × efficiency). Other fuels: price ÷ (Btu per unit × efficiency): propane 91,452 Btu/gal, heating oil 138,500 Btu/gal, natural gas 100,000 Btu/therm, electricity 3,412 Btu/kWh. Species heat values are for air-dried wood; green wood delivers much less. Sources: Utah State University Extension, Wood Heating; U.S. EIA Btu conversion factors; EPA Burn Wise, Frequent Questions. Estimates only: your stove, wood moisture and habits change the real number.

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How the math works

Heat per cord for air-dried wood comes from Utah State University Extension (the same values as our firewood BTU chart).
Delivered cost = price per full-cord equivalent ÷ million Btu per cord ÷ stove efficiency. A full cord is 128 cubic feet stacked; enter the real volume if you buy a face cord or rick.
Other fuels use EIA conversion factors: propane 91,452 Btu per gallon, heating oil 138,500 Btu per gallon, natural gas 100,000 Btu per therm, electricity 3,412 Btu per kWh (EIA).
Typical EPA efficiencies are about 71% for non-catalytic and 78% for catalytic stoves (HHV) (EPA). Use your stove’s own figure if it’s on the label.

Prices are example defaults; replace them with your own. Wet wood delivers far less heat than these figures; see how to season firewood.