How Much Firewood Do I Need? (cords per season)
Cords per heating season from your heat need, the species you burn, and your stove's efficiency.
How many cords do I need?
Seasonal estimates from Illinois Extension / Nebraska Forest Service. Use the calculator above for your own house and species.
| Use | Full cords per season |
|---|---|
| Whole-house heat | 4½ to 7 |
| Partial or supplemental heat | 1½ to 3 |
| Occasional fireplace | about ½ |
Worked example
Maryland Extension's fuel-cost table uses a season of 80 million Btu. Red oak holds 24.6 million Btu per cord (USU). In a unit running at 50% efficiency, the same basis Missouri Extension uses in its fuel comparison table, that comes to 80 ÷ (24.6 × 0.50) ≈ 6.5 cords.
How it works
Cords needed = seasonal heat ÷ (heat per cord × efficiency). For seasonal heat, convert last winter's fuel bills to the heat actually delivered (fuel energy × the old system's efficiency). For efficiency, use your stove's EPA label or manual. Burning wood that isn't seasoned lowers the useful heat.
Questions
How many cords does it take to heat a house for a winter?
Illinois/Nebraska Extension gives 4½ to 7 full cords for whole-house heat, 1½ to 3 as partial heat, and about half a cord for an occasional fireplace.
Which firewood gives the most heat?
In USU's table, Osage-orange (32.9 million Btu per cord), Gambel oak (30.7) and white oak (29.1) are at the top.
Why does efficiency matter so much?
Only the efficiency share of the wood's heat reaches your rooms, so doubling efficiency halves the wood you need.
Sources
Guides
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