Firewood Cord Calculator
Quick answer: A full cord is legally 128 cubic feet — a ranked, tightly stacked 4 × 4 × 8 ft pile. Divide your stack's cubic footage by 128 to get cords; a 16-inch face cord (4 × 8 ft × 16 in) is about 42.67 cu ft, or exactly one-third of a cord. A 4 × 8 × 4 ft stack is exactly 1 cord.
Make sure you are getting what you paid for. Measure your firewood stack's length, height, and depth, and this firewood cord calculator converts it to cubic feet, full cords, and face cords — using the legal 128 cu ft cord definition.
Enter your numbers
Your results
Legal cords only. "Face cord", "rack", "pile", and "truckload" are not legal units — firewood may only be sold by the cord or a fraction of a cord (NIST).
How to use this calculator
Stack the wood first: pieces in a line or row, touching and parallel, stacked as compactly as possible. Measure the stack's length, height, and depth in feet, enter them, and the calculator does the rest.
The headline result is full cords (stack volume ÷ 128). Below it you get the raw cubic footage and the equivalent face cords, handy when a seller prices by the face cord.
How this is calculated
Stack volume = length × height × depth (cubic feet). Full cords = volume ÷ 128. Face cords = volume ÷ 42.6667, where 42.6667 cu ft is exactly one-third of a cord — the volume of a 4 ft × 8 ft row of 16-inch pieces (4 × 8 × 16/12 = 42.6667).
Inputs: all three dimensions in feet. If your pieces are 16 inches, enter depth as 1.33 ft (16 ÷ 12); the calculator converts the face-cord equivalent on that basis.
Assumptions and edge cases: the cord definition assumes wood that is "ranked and well stowed" — a loose or heaped pile of the same wood occupies more space and is not a cord, so measure the ranked stack, not the truck bed. Bark, odd piece lengths, and air gaps reduce the true wood volume; this calculator reports the stack volume only. A face cord is a trade convention (one row of a cord), not a legal unit of sale.
Worked example
A stack 4 ft high × 8 ft long × 4 ft deep: volume = 4 × 8 × 4 = 128 cu ft = 128 ÷ 128 = 1.00 cord. A 4 ft × 8 ft face cord of 16-inch pieces: volume = 4 × 8 × (16 ÷ 12) = 42.67 cu ft = 42.67 ÷ 128 = 0.333 cord, i.e. exactly one-third of a cord.
Reference data
| Full cord (legal) | 128 cu ft — e.g. 4 ft × 4 ft × 8 ft, ranked and well stowed |
|---|---|
| ½ cord | 64 cu ft — e.g. 4 ft × 4 ft × 4 ft |
| ¼ cord | 32 cu ft — e.g. 4 ft × 2 ft × 4 ft |
| Face cord, 16-in pieces (trade convention) | ≈ 42.67 cu ft — 4 ft × 8 ft × 16 in ≈ ⅓ cord. Not a legal unit of sale. |
Source: NIST, "Burned When Buying Firewood" consumer fact sheet — a cord must equal 128 cubic feet and, like a foot or a gallon, is defined by law (NIST Handbook 130, §2.4.1.2, the model regulation adopted by US state weights-and-measures agencies) — https://www.nist.gov/document/ncwm-firewood-factspdf. Current as of 2026.
Method & sources
Stack volume is measured directly from your three dimensions; cord fractions are exact arithmetic on the 128 cu ft legal cord. The face-cord divisor (42.6667 = 128 ÷ 3) is derived from the 16-inch face-cord convention. The only estimates are your measurements of the stack itself.
- NIST — "Burned When Buying Firewood": cord = 128 cubic feet, defined by law; firewood may only be sold by the cord or fractions — nist.gov
- NIST Handbook 130, §2.4.1.2 — model firewood regulation ("ranked and well stowed") adopted by US state weights-and-measures agencies.
Frequently asked questions
How many cubic feet is a cord of firewood?
A full cord is exactly 128 cubic feet: a stack 4 feet high, 4 feet deep, and 8 feet long, with the wood ranked (touching, parallel) and well stowed. This is the legal definition under NIST Handbook 130.
What is a face cord?
A face cord is one row of a cord — for example 4 ft high × 8 ft long with 16-inch pieces, which is about 42.67 cubic feet or one-third of a cord. It is a trade convention, not a legal unit of sale.
How do I measure my firewood stack?
Stack the wood in a line with pieces touching and parallel, as compact as possible, then measure length × height × depth in feet. Multiply the three to get cubic feet, then divide by 128 for cords.
Why does my stack show fewer cords than the seller claimed?
Loose piles, air gaps, bark, and heaped (unstacked) loads all measure less than a ranked stack of the same wood. Only a neatly stacked, measured volume counts — measure the ranked stack, not the truck bed.