Total BTU Output
40.8M BTU
Rated
48M BTU
Oil Equiv.
294.6 gal
1 cord = 128 cu ft (4′ \u00D7 4′ \u00D7 8′ stacked)
Inputs
Result
Rated BTU = 24M × 2 cords = 48M BTU. Seasoned wood factor = 0.85. Actual BTU = 48 × 0.85 = 40.8M BTU. Oil equivalent = 40,800,000 / 138,500 = 294.6 gallons.
Inputs
Result
Rated BTU = 15.7M × 3 = 47.1M BTU. Green wood factor = 0.6. Actual BTU = 47.1 × 0.6 = 28.3M BTU. Despite 3 cords of pine, the actual output is lower than 2 cords of seasoned oak.
BTU per cord varies greatly by species. Hickory is the highest at 27.7 million BTU per cord. Oak and maple produce about 24 million BTU. Pine is the lowest common species at 15.7 million BTU per cord. These are rated values for dry wood; moisture reduces actual output.
| Species | BTU/Cord (M) | Weight/Cord | Coals |
|---|---|---|---|
| Hickory | 27.7M | 4,327 lbs | Excellent |
| Oak | 24.0M | 3,768 lbs | Excellent |
| Maple | 24.0M | 3,680 lbs | Excellent |
| Birch | 20.8M | 3,040 lbs | Good |
| Cherry | 20.4M | 2,928 lbs | Good |
| Ash | 20.0M | 3,440 lbs | Good |
| Elm | 19.5M | 2,900 lbs | Good |
| Pine | 15.7M | 2,610 lbs | Poor |
Moisture content dramatically reduces heat output. Green wood (30–50% moisture) produces only about 60% of its rated BTU because energy is wasted evaporating water. Seasoned wood (20% moisture) produces about 85% of rated BTU. Kiln-dried wood (under 10%) delivers nearly 100%.
The average home using wood as the primary heat source burns 3–5 cords per winter in cold climates, 2–3 cords in moderate climates. A supplemental wood stove typically uses 1–2 cords. Using a high-BTU species like oak or hickory reduces the cords needed.
Firewood at $250/cord for seasoned oak costs about $12.25 per million BTU. Natural gas at $1.20/therm costs $12 per million BTU. Heating oil at $3.50/gallon costs $25 per million BTU. Wood is competitive with gas and much cheaper than oil or electricity.
| Fuel | Unit Cost | BTU/Unit | $/Million BTU |
|---|---|---|---|
| Firewood (oak) | $250/cord | 24M BTU | $12.25 |
| Natural gas | $1.20/therm | 100K BTU | $12.00 |
| Propane | $2.80/gal | 91.5K BTU | $30.60 |
| Heating oil | $3.50/gal | 138.5K BTU | $25.27 |
| Electricity | $0.13/kWh | 3,412 BTU | $38.10 |
Oak and hickory are the best overall species. They produce high BTU, burn slowly with excellent coals, create minimal sparks, and produce low smoke when seasoned. Ash is excellent for beginners because it splits easily and burns well even when slightly green.
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Last Updated: Mar 9, 2026
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