🪓 Heating

Firewood Cord to BTU

Convert a cord, face cord, rick or cubic metre of firewood into BTU, weight and heating-oil equivalent. Choose the species and moisture, then press Convert.

Written and reviewed by SM Arijul Islam · Last reviewed 29 October 2026 · Editorial standards · Report an error

About the Firewood Cord to BTU

A full cord is 128 cubic feet of stacked firewood — 4 ft × 4 ft × 8 ft. A face cord is one-third of that, 4 ft × 8 ft × 16 in, and a rick is usually the same. The volume is only half the story: a cord of oak weighs and heats far more than a cord of pine, and wet wood wastes energy boiling off water.

The BTU figures here are for seasoned wood at about 20% moisture. Green wood at 50% moisture loses roughly a third of its usable heat to evaporation, and it burns poorly besides. Split, stack and cover the wood for at least a season before relying on the number.

How the calculation works

1 cord = 128 ft³ = 3.6246 m³.
1 face cord = 1 rick = 1/3 cord ≈ 42.67 ft³.
Usable BTU = cord BTU × moisture adjustment.
1 gallon of heating oil ≈ 138,500 BTU; 1 gallon of propane ≈ 91,500 BTU.

Reference values

Approximate heating values at 20% moisture
Species	Million BTU/cord	Seasoned weight/cord
Oak	24.0	3,800 lb
Ash	23.0	3,600 lb
Walnut	22.0	3,300 lb
Birch	21.5	3,500 lb
Maple	21.0	3,400 lb
Cherry	20.0	3,200 lb
Fir	16.0	2,500 lb
Pine	15.0	2,600 lb
Spruce	14.5	2,300 lb
Poplar	14.0	2,300 lb

Worked example: a cord against heating oil

A full cord of seasoned oak at 24 million BTU is roughly equivalent to 173 gallons of heating oil (24,000,000 ÷ 138,500) or 262 gallons of propane. A face cord is one-third of that: 8 million BTU, about 58 gallons of oil. A cord of pine at 15 million BTU is worth about 108 gallons of oil.

Those equivalents assume a modern stove or boiler running at a reasonable efficiency. An open fire loses most of the heat up the chimney, so the useful comparison is smaller. Seasoning matters too: green wood spends part of its heat boiling off water instead of warming the room.

Frequently asked questions

Is a face cord a full cord?

No. A face cord is 4 ft × 8 ft × the length of the pieces, usually 16 in, so it is one-third of a full cord. Some sellers use the terms loosely; confirm the volume.

How long should firewood season?

Six to twelve months for most hardwoods, longer for oak. Split it, stack it off the ground and cover the top, leaving the sides open for airflow.

Does hardwood always heat better?

Per cord, usually yes. Per pound, dry wood of any species has similar energy content; hardwood is denser, so a cord weighs more and releases more heat.

Does a cord always contain the same amount of wood?

No. A cord is a stacked volume, so the amount of solid wood depends on how well it is split and stacked. Loose stacking can leave 20–30% air; a well-stacked cord contains more usable wood.

Sources and standards

The heat available from firewood depends on species and moisture content, not on volume alone: a cord is 128 cubic feet of stacked wood, and usable heat falls sharply above roughly 20% moisture. The USDA Forest Products Laboratory publishes the species densities and heating values behind the figures here.