Off Grid Collective
Back to Calculators

Firewood & Heating Fuel Calculator

Estimate how many cords of firewood you need per heating season based on your space, climate, and wood type.

New to off-grid? Start with our 3-question path finder for a personalized off-grid guide.

Space & Climate

Your heated floor area and local climate determine your seasonal heat demand.

80.0 m²

5 months of heating per year

e.g. UK, N. India, Midwest US, AU south

7 BTU/hr/ft²

Heat loss rate for Moderate (Temperate)

Stove & Wood Species

Wood species and stove efficiency significantly affect how much wood you actually burn.

Hard maple, clean burn, popular choice

70%
20% (open fireplace)90% (high-efficiency insert)

Species Comparison (BTU/cord)

White Oak: 26.4M
Red Oak: 24.6M
Sugar Maple: 24.0M
Ash: 23.6M
Yellow Birch: 21.8M

Calculation Assumptions

  • Heat demand = floor area × climate heat-loss factor (BTU/hr/ft²) × 16 active heating hours/day × heating season days.
  • Cords needed = total BTU demand ÷ (species BTU/cord × stove efficiency). BTU values assume a full cord (4×4×8 ft, 128 ft³) of air-dried wood seasoned 6+ months.
  • Storage volume = 1 cord = 128 ft³ = 3.62 m³. Allow additional space (15–20%) for ventilation between stacked logs.
  • Cost estimates are approximate delivered prices in United States. Prices vary significantly by species, location, and whether you cut/split yourself.
  • Assumes 16 active heating hours/day. Adjust the heating season length to account for shoulder seasons where you heat less frequently.

Heating Summary

Updates live as you adjust inputs.

Firewood Needed

0.8cords/year

Sugar Maple · 70% stove efficiency

Storage Space Required

103ft³

0.8 cords × 128 ft³/cord

Also: 3 m³

Estimated Annual Cost

$256

Based on ~$320/cord delivered in United States. Prices vary by species, season, and supplier.

Annual Heat Demand

13.5M BTU

861 ft² · 7 BTU/hr/ft² · 20 weeks