Firewood Cord Calculator: How Many Cords (and BTUs) Are in Your Stack?
Firewood cord calculator: enter stack length, height and piece length to get cords from the legal 128 cubic foot definition, plus heat by species.
Affiliate disclosure: product links on this page go to Amazon or to the maker's own store. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you; links to makers' own stores earn us nothing. No retailer or brand sees our picks before they are published or has any say in them. How we choose.
A cord is the wood in 128 cubic feet when ranked and well stowed, so a tight 4 by 4 by 8 foot stack is one cord. A single row 8 feet long and 4 feet high of 16 inch pieces is 42.7 cubic feet: one third of a cord, whatever the seller calls it.
Enter your stack below. Pick a species to see the heat it holds, using Missouri Department of Conservation's figures.
How much wood is in your stack?
Rows of pieces placed one behind another
Cords
0.33
42.7 cubic feet
Share of a full cord
33%
A 4 x 8 ft single row of 16 in pieces is one third of a cord
Heat in this stack
8.4 million Btu
Red oak: 25.3 million Btu per cord
A cord is the wood in 128 cubic feet when ranked and well stowed (NIST Handbook 130's definition, as Connecticut adopts it); a full cord is commonly 4 x 4 x 8 feet. Measure a tightly stacked pile: loose or crisscrossed wood holds less. Heat values are Missouri Department of Conservation's million Btu per cord; the article gives no moisture basis, so treat them as a ranking of dry wood, not a guarantee.
How it works
Volume is length x height x depth, where depth is the piece length times the number of rows. Divide by 128 for cords. The 128 cubic foot cord, ranked and well stowed, is NIST Handbook 130's definition as Connecticut adopts it; Connecticut also bars selling firewood as a "face cord", "rack", "pile" or "truckload".
| Stack | Cubic feet | Cords |
|---|---|---|
| 4 x 4 x 8 ft | 128 | 1 |
| 8 ft long, 4 ft high, one row of 16 in pieces | 42.7 | 0.33 |
| 8 ft long, 4 ft high, two rows of 16 in pieces | 85.3 | 0.67 |
| 12 ft long, 5 ft high, one row of 18 in pieces | 90 | 0.70 |
Heat values
| Species | Million Btu per cord |
|---|---|
| Osage orange | 30.7 |
| Hickory | 29.1 |
| Black locust | 28.1 |
| White oak | 27.0 |
| Red oak | 25.3 |
| Ash | 23.6 |
| Elm | 21.4 |
| Shortleaf pine | 19.0 |
| Eastern redcedar | 18.9 |
| Boxelder | 17.5 |
| Cottonwood | 16.1 |
Full chart and what it means: firewood BTU chart. Measuring a delivery: how to measure a cord of wood.
Tips
- Measure tightly stacked wood; loose or crisscrossed wood holds less.
- Get a delivery ticket: Connecticut requires one showing the quantity and price for unpackaged firewood.
- Season before burning: EPA says wood burns best below 20 percent moisture; see how to season firewood.
Frequently asked questions
How many cubic feet is a cord of wood?
128 cubic feet of ranked and well-stowed wood, the definition in NIST Handbook 130 as Connecticut adopts it; commonly a 4 by 4 by 8 foot stack.
How much is a face cord?
"Face cord" has no legal size, and Connecticut bars it in firewood sales. A common single row 4 by 8 feet of 16 inch pieces is one third of a cord.
How many BTUs in a cord of oak?
Missouri Department of Conservation lists red oak at 25.3 and white oak at 27.0 million Btu per cord.
What firewood has the most heat?
On Missouri's chart, Osage orange (30.7), hickory (29.1) and black locust (28.1 million Btu per cord) lead.
How do I know if I got a full cord?
Stack the wood tightly, multiply length by height by depth in feet, and compare with 128 cubic feet.
Sources
- Firewood and Stove Wood Regulations, Connecticut Department of Consumer Protection
- Home Heating, Missouri Department of Conservation
- Best Wood-Burning Practices, US EPA Burn Wise
Related guides
Firewood BTU Chart: Heat Value by Wood Species
Which firewood gives the most heat per cord, by species.
How to Measure a Cord of Wood (and What a Face Cord Really Is)
Check a firewood delivery: 128 cubic feet, measured the right way.
How to Season Firewood: Splitting, Stacking and Drying Time
EPA's rules for drying firewood, and how to tell when it is ready.