How Many Cords of Firewood Do You Need for Winter?
Homes that rely on wood for main heat burn anywhere from about 1–2 cords in a small house in a mild climate to 7–8 cords in a large house in a cold one. No single number fits everyone, so here is a way to calculate yours.
Rule-of-thumb ranges
Published guidance commonly suggests roughly 2–3 cords per 1,000 sq ft in a cold climate and 1–2 cords in a warm one, with wood as the main heat source. Treat these as starting points.
Calculate it from your fuel bills
Example: you burned 600 gallons of propane in an 85%-efficient furnace. Delivered heat = 600 × 91,452 BTU × 0.85 ≈ 46.6 MMBtu. A cord holds about 20 MMBtu (EIA average); at 70% stove efficiency that is 14 MMBtu useful. 46.6 ÷ 14 ≈ 3.3 cords. Add a 10–20% buffer and plan for about 4.
Dense hardwoods hold more heat per cord than softwoods, and wet wood delivers less. Adjust upward if you burn softwood or unseasoned wood.
Track your first winter
Write down how many cords you start with and how much is left in spring. After one or two seasons you will have your own number, which beats any calculator. When buying, check the unit with the cord converter.
Worked examples: three homes
These use illustrative heat needs, the 20 million BTU average cord and a 70%-efficient stove (14 million useful BTU per cord). Swap in your own heat need from the method above.
| Home | Heat from wood (MMBtu) | Cords |
|---|---|---|
| Small, well insulated, mild climate | 30 | 2.1 |
| Medium, average insulation | 50 | 3.6 |
| Large, cold climate | 90 | 6.4 |
How species and stove efficiency change the answer
For the 50 MMBtu home, dense hardwood at 25.9 million BTU gross (18.1 million useful) needs about 2.8 cords, while pine at 17.1 million (12.0 useful) needs about 4.2. Efficiency matters just as much: at 60% a 20 million BTU cord yields 12 million useful BTU and the home needs 4.2 cords; at 80% it yields 16 million and needs 3.1. See best firewood by BTU for species values.
If wood only supplies part of your heat
Scale the heat need to the share wood will cover. If wood provides half of that 50 MMBtu and your propane or oil system covers the rest, you need about 1.8 cords. Compare what the other half costs in is firewood cheaper than propane?
Where to store it
A cord stacked 4 feet high covers about 32 square feet of floor (8 ft × 4 ft). Stacked 6 feet high it needs about 21 square feet. Four cords at 4 feet high is roughly 128 square feet, so plan space before you order. Stack off the ground with room for airflow, and keep the top covered (seasoning guide).
Common mistakes
- Counting face cords as full cords; check the log length.
- Planning on unseasoned wood, which delivers less usable heat.
- Skipping the buffer; one cold snap can use up a tight estimate.
- Ordering late: wood bought in autumn is often not dry enough for that winter.
FAQ
How much space does a cord take?
A tightly stacked cord is 128 cubic feet (4 × 4 × 8 ft). Leave extra room around it for airflow.
Can I buy face cords instead?
Yes, but check the log length first. See our guide to face cord vs full cord.
How much wood for an occasional fireplace?
Far less than a stove used as main heat. Start small and track what you burn.