Firewood Cord Calculator

Background.

A firewood cord calculator converts a stack or truck load of wood into cubic feet, full cords, fractional cords, and cost. The canonical use case is a homeowner comparing a delivered stack, a pickup load, a Forest Service firewood permit load, or a seller's advertised "face cord" against the standard full cord. A full cord of firewood is 128 cubic feet when tightly stacked, commonly described as 4 feet high by 4 feet wide by 8 feet long. If a stack is 16 feet long, 4 feet high, and 16 inches deep, it contains about 85.33 cubic feet, or two-thirds of a cord.

People search for this because firewood sellers and buyers often use informal terms. "Cord" is a standard volume unit. "Face cord," "rick," "truckload," and "pickup load" vary by piece length, bed size, stacking height, and local custom. A face cord of 16 inch pieces is much smaller than a full cord even if the front face is 8 feet by 4 feet. The calculator keeps the measured dimensions visible so users can compare offers by cubic feet and full-cord equivalent instead of relying on ambiguous names.

The formula is simple rectangular volume. Multiply stack length by height by depth. If piece length is entered in inches, divide by 12 to get feet. Then divide cubic feet by 128. Cost follows from cords times price per cord, with optional delivery. The important implementation detail is to treat cord conversion as a volume conversion, not a weight conversion. Different wood species, moisture content, and stacking tightness can change weight and heat value. A cord of dry oak and a cord of wet pine occupy the same stacked volume but do not provide the same fuel value or handling weight.

Primary sources support both the volume unit and safe-use context. USDA Forest Service firewood permit pages commonly define a cord as 128 cubic feet and use load-ticket systems for partial cords. NIST unit tables and weights-and-measures publications support customary volume relationships. EPA Burn Wise materials emphasize good wood-burning practices, wood storage, and air pollution context. Those sources justify a calculator that measures volume accurately while warning that dryness, appliance certification, local burning rules, and transport limits are separate questions.

For engineering, the output should prioritize full-cord equivalent and cubic feet. Fraction labels such as one-half or two-thirds are helpful for users, but the exact decimal cord value should remain available for cost and comparison. The calculator can optionally show face-cord equivalents for common 16 inch, 18 inch, and 24 inch piece lengths, but it should not make "face cord" the primary result because it is less standard than a full cord. The tested core is stack volume, depth conversion, cords, and cost.

A dependable implementation should also show how stack depth was obtained. Buyers may enter measured stack depth, average piece length, or a seller label such as face cord. The calculator should convert those into feet and cubic feet before using the 128 cubic foot cord divisor.

What is firewood cord calculator?

A cord is a stacked-volume unit used for firewood. A full cord is 128 cubic feet of stacked wood, commonly represented by a stack 8 feet long, 4 feet high, and 4 feet deep. The wood is stacked with air gaps, so a cord is not 128 cubic feet of solid wood fiber. It is a standard way to measure a pile of cut and split firewood.

The key vocabulary is cord, face cord, stack depth, piece length, cubic feet, and price per cord. Stack depth is usually the cut length of the firewood pieces. A face cord often means a stack 8 feet long by 4 feet high by one piece length deep, but the depth can vary. That is why the calculator asks for actual dimensions. The calculator is valid for comparing measured stacks, loads, and prices. It does not estimate heat output, moisture content, species energy value, legal sale rules in every state, safe vehicle loading, or whether firewood is properly seasoned.

For best results, users should measure stacked wood after delivery when possible and keep species, dryness, delivery, and stacking service separate from the volume calculation. This prevents a fair volume comparison from being confused with fuel quality.

How to use this calculator.

1. 01Measure the stack length in feet.
2. 02Measure the stack height in feet.
3. 03Enter stack depth or average piece length.
4. 04Enter the number of identical stacks or loads.
5. 05Enter price per cord and delivery fee if comparing cost.
6. 06Review cubic feet, full-cord equivalent, and total price.
7. 07Check local firewood sale rules, moisture, and transport limits separately.

The formula.

The formula starts with a rectangular stack. Length times height times depth gives cubic feet. If the stack is 16 feet long and 4 feet high, the front face is 64 square feet. If the pieces are 16 inches long, depth is 16 divided by 12, or 1.333333 feet. Multiplying 64 by 1.333333 gives about 85.333 cubic feet. If there are multiple identical stacks, multiply by the number of stacks.

Cord conversion divides stacked cubic feet by 128. This is the key standardized step. A pile with 85.333 cubic feet is 85.333 divided by 128, or about 0.666667 cords. If the seller charges by full cord, cost is decimal cords times price per cord. At 300 dollars per cord, two-thirds of a cord costs about 200 dollars before delivery. Cost per cubic foot is total cost divided by stack volume and can help compare sellers who use different labels.

The calculator should not treat firewood volume as heat value. Moisture content, species, seasoning, split size, and storage conditions affect useful heat. Wet wood can be heavy and inefficient. A loose thrown pile can contain less wood per apparent volume than a tightly stacked pile. For that reason, the calculator should ask for stacked dimensions and should warn users that "truckload" estimates depend on how the wood is stacked and how full the bed is.

Rounding should be transparent. Cords can be shown to two decimal places for readability, but cost should be calculated from the unrounded value. Fraction labels can be generated for common values such as 0.25, 0.50, 0.67, and 0.75, but the decimal should remain visible. If local rules require firewood to be sold in cords or fractions of cords, the calculator should support that display without hiding the measured cubic feet.

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.