The Field Calculators → Food & Storage
Food & Storage
Firewood: cords & heat
What's actually in that stack, how much heat is in it, and how much you need for the winter.
Result
Stack length16 ft
Stack height4 ft
Log length (stack depth)16 in
SpeciesOak / sugar maple / beech (~24M)
Heat needed for the season60 million BTU
Stove efficiency70 %
This stack is
0.67 cords
A full cord is 128 cubic feet stacked — 4 × 4 × 8 ft.
Usable heat in it
11.2 million BTU
After 70% stove efficiency.
Cords you need for the season
3.6 cords
Still to cut
2.9 cords
Season-ahead rule
Cut 7.1 cords
Always be a year ahead. Wood cut this spring burns next winter.
What this will not do
- Seasoning is worth more than species. Wood at 20% moisture gives you the BTU on the chart; wood at 35% spends a large share of its energy boiling off its own water, makes creosote, and is how chimney fires start. Split it, stack it off the ground, cover the top only, and give it a year — two for oak.
- A 'face cord' or 'rick' is not a cord. It's one stack 4 ft high and 8 ft long at whatever the log length is — commonly a third of a cord. This is the most common firewood ripoff and this calculator is how you check.
- Moisture meter, $20. Split a piece and test the fresh face. It ends every argument.