Calculate firewood volume, cost, BTU output, and stacking requirements. Compare wood types and alternative fuel costs for home heating.
Buying firewood is confusing — vendors sell by the cord, face cord, rick, truckload, and other inconsistent units. A "cord" is the only legally standardized measurement: a stack measuring 4' × 4' × 8' (128 cubic feet). Everything else varies by region and seller.
This cord of wood calculator helps you figure out how many cords you need for the season, what they'll cost, how much heat you'll get, and how your firewood heating costs compare to natural gas, propane, oil, and electric alternatives. The wood species comparison shows BTU output, price, and drying time for eight common firewood types. It also keeps cord count, stack volume, and seasonal heat output together so a quote is easier to check.
Whether you're buying your first cord or planning a full winter's supply, the calculator covers volume, stacking requirements, weight estimates, and the critical question: is wood heat actually cheaper than your alternatives?
Use this calculator to standardize firewood purchases into full cords, estimate seasonal heat output, and compare wood heat against other fuels. It is useful when sellers quote face cords, truckloads, or other inconsistent units and you need a common basis for cost and volume. That helps you compare offers using the same measurement before you order or stack wood.
1 cord = 4' × 4' × 8' = 128 cu ft. 1 face cord = 1/3 cord (4' × 8' × ~16"). BTU varies by species (15-26M BTU/cord). Season estimate: (home_sqft × 50 BTU/sqft × heating_pct × 150 days) / (BTU_per_cord × 1,000,000).
Result: Cost: $1,100, 96M BTU, 14,000 lbs, need ~3 stacks
4 cords of hardwood mix at $275/cord costs $1,100 and provides 96 million BTU. At 3,500 lbs/cord, that's 14,000 lbs of wood. In 4' × 4' stacks 8' wide, you'll need 3 stacks. For a 2,000 sq ft home at 50% wood heat, the season estimate is about 3.1 cords — so 4 gives you a comfortable margin.
The cord is the only federally standardized firewood measurement in the US. Unfortunately, sellers often use non-standard terms: "face cord," "rick," "rack," "truckload," and "pile" all mean different things depending on where you live. A face cord is usually 1/3 of a cord, but some areas define it as 1/2. When buying firewood, always ask for the dimensions and do the math: length × height × depth ÷ 128 = cords.
Freshly cut "green" wood has 40-60% moisture content. Properly seasoned firewood should be below 20%. The moisture content dramatically affects heat output — burning green wood wastes up to 40% of the potential BTU evaporating water. Stack firewood in a single row with good sun exposure and air circulation. The top should be covered to shed rain, but sides should be open. Most hardwoods need a full year of stacking to properly season.
The heat output from firewood depends not just on species but on your stove or fireplace efficiency. An open fireplace is only 10-15% efficient (most heat goes up the chimney). A modern EPA-certified wood stove is 70-80% efficient. A fireplace insert falls between at 50-70%. When comparing wood to other fuels, multiply the BTU by your appliance efficiency for true heating value.
A cord is a legal unit of measurement for firewood: a neatly stacked pile measuring 4 feet high × 4 feet deep × 8 feet long = 128 cubic feet. The wood pieces should be stacked parallel, not thrown in a heap.
A face cord (or rick) is one face of a full cord — typically 4' high × 8' long × one log length deep (usually 16"). It's roughly 1/3 of a full cord. Many sellers advertise face cords at prices that look cheap until you realize you're getting 1/3 the wood.
A well-insulated modern home using wood as the primary heat source typically burns 3-5 cords per season in northern climates. Supplemental use (weekends, ambiance) might need 1-2 cords. The calculator estimates based on your home size and heating percentage.
Dense hardwoods like oak, maple, and hickory burn hottest and longest (22-26M BTU/cord). Medium-density woods like birch and cherry are good all-around choices. Softwoods like pine burn fast and are best for kindling or shoulder-season fires. Always burn seasoned (dry) wood.
It depends on local prices. In most rural areas, firewood is significantly cheaper than propane or oil per BTU. It's roughly competitive with natural gas and usually more expensive than gas in areas with cheap utility service. The fuel comparison table shows your specific scenario.
Hardwoods need 12-18 months of air drying to reach optimal moisture content (~20%). Softwoods dry faster, typically 6-9 months. Burning green (unseasoned) wood wastes energy evaporating moisture, produces excessive creosote, and generates much more smoke.