Firewood Cord Calculator

Background.

A "$150 face cord" can be a fair price or an expensive one, and the ad rarely says which. A face cord is a stack 4 feet high and 8 feet long but only one piece of wood deep, so its volume depends on how long the pieces were cut. With 24-inch wood it is half a cord, which puts the $150 at $300 a cord; with 16-inch wood it is a third of a cord, and the same $150 works out to $450 a cord.

The full cord is the fixed point. It is 128 cubic feet of stacked wood, the space filled by a pile 4 feet high, 4 feet deep and 8 feet long. In states that follow the national model weights-and-measures rules (NIST Handbook 130), firewood has to be sold by the cord or a stated fraction of one, measured with the wood "ranked and well stowed" — pieces in rows, touching and parallel, packed compactly — and names such as face cord, rick or pickup load are not recognised measures. Personal-use cutting permits on national forests are issued in cords as well.

Checking what you bought is a tape-measure job. Take the length of the stack and its height in feet, and its depth, which for a single row is the length of the pieces in inches. Multiply them, divide by 128, and you have the stack as a share of a cord. Several identical stacks or loads can be counted at once, and a price per cord plus a delivery fee turn the volume into a total and a cost per cubic foot, so offers sold under different names can be lined up against each other.

A cord counts space, not wood. The 128 cubic feet include the air between pieces, so crooked, knotty splits fill a stack with less wood than straight ones, and a loose heap takes up more room than the same wood stacked. Nor does a cord say how much heat you are buying: a cord of dense, dry oak and a cord of green pine occupy the same space and burn very differently.

What is firewood cord calculator?

A cord is a unit of stacked volume: 128 cubic feet, the space taken by a stack 8 feet long, 4 feet high and 4 feet deep. A classic full cord is three rows of 16-inch pieces, or two rows of 24-inch pieces, built to that 4 × 8 ft face. Fractions are shares of the same 128 cubic feet, so a half cord is 64 cubic feet and a quarter cord 32. A face cord is a single row with the 4 × 8 ft face, so its share of a cord is set entirely by the piece length. In metric terms a cord is about 3.62 cubic metres of stacked wood, a useful bridge when wood is quoted by the stacked cubic metre, as it often is in Europe. Because the cord measures the stack rather than the wood in it, the volume is the same whether the stack is oak or pine, wet or dry.

How to use this calculator.

1. 01Measure Stack length in feet along the face from end to end. If the ends are built as crisscrossed pillars, measure only the straight row between them, since the pillars are much looser than the row.
2. 02Measure Stack height in feet at several points and enter the average; stacks sag in the middle and settle as the wood dries. Readings of 3.5, 4, 4.5 and 4 ft average to 4 ft.
3. 03Enter Stack depth or average piece length in inches. For a single row this is the typical piece length, so measure a handful of pieces and average them. For two rows back to back, enter the full depth: 32 in for two rows of 16-inch wood. If the rows stand apart with a gap between them, add the two piece lengths rather than measuring across the gap.
4. 04Set Number of identical stacks or loads when you have several identical stacks. The volume is multiplied by this number, so stacks of different sizes need separate runs.
5. 05Add the Price per cord and, if the seller charges one, the Delivery fee. The fee is added once to the whole order, so enter the combined charge if each load is billed separately. A face-cord price has to be converted to a per-cord price first.

The formula.

Cords = L × H × (D ÷ 12) × n ÷ 128. L is the stack length and H the height, both in feet; D is the depth in inches, divided by 12 to put it in feet; n is the number of identical stacks; and 128 is the cubic feet in one cord. Everything before the last division is the stacked volume in cubic feet.

The four measurements multiply, so each moves the answer in proportion: a stack 10% taller is 10% more cord. Depth is the one that differs most between offers, because it is fixed by how the wood was cut. Going from 16-inch to 24-inch pieces in the same 4 × 8 ft face raises the volume by half, from a third of a cord to a half.

The money follows from the volume. Wood cost is cords × price per cord. Total cost adds the delivery fee, once, however many stacks you entered. Cost per cubic foot is total cost ÷ stacked volume, with delivery included, which is the figure to compare when sellers quote in different units or one charges for delivery and the other does not. With no price and no fee it reads 0.

The model is a rectangular box filled to the edges you measured. That describes a well-made stack — straight rows, square ends, a level top — which is what the legal phrase "ranked and well stowed" asks for. It describes a stack with a sagging middle or a heaped top less well, which is why averaging several height readings matters, and it cannot describe a loose heap at all until the wood is stacked. It also says nothing about how much solid wood is inside the box: crooked, forked or very large pieces leave more air than straight, evenly split ones.

A worked example.

Frequently asked questions.

References& sources.

1. [1]U.S. Department of Agriculture, Forest Service (2025). "Black Hills National Forest Firewood Permit." USDA Forest Service.
2. [2]U.S. Department of Agriculture, Forest Service (2025). "Sawtooth National Forest Firewood Permits." USDA Forest Service.
3. [3]U.S. Environmental Protection Agency (2026). "Burn Wise." EPA.
4. [4]National Institute of Standards and Technology (2026). "NIST Handbook 133, Appendix E: General Tables of Units of Measurement." U.S. Department of Commerce.
5. [5]National Institute of Standards and Technology (2008). "Guide for the Use of the International System of Units (SI), NIST Special Publication 811." U.S. Department of Commerce.