A full cord of firewood is 128 cubic feet of tightly stacked wood, the same space as a pile 8 ft long, 4 ft high, and 4 ft deep. To find out how much wood is in any stack, our firewood calculator multiplies length × height × piece length (in feet) × rows, then divides by 128. As a rule of thumb, a single 8 × 4 ft row of 16 in pieces, the size often sold as a "face cord," holds only about one-third of a full cord.
Enter your stack's measurements below. Add the seller's price if you have one, and the calculator turns it into a price per full cord.
How to measure a stack of firewood
- Check that it is stacked tight. A cord is measured as wood "ranked and well stowed": pieces in a row, parallel, touching, and stacked compactly, as Connecticut's firewood regulations put it. Montana State University Extension notes that a loose cord can take up about 30 percent more space than a stacked one, so a thrown pile always looks bigger than it is.
- Measure the length along the face of the stack, in feet. If the ends lean or taper, measure about halfway up.
- Measure the height at three or four points and use the average. Woodpiles are rarely level.
- Measure the piece length. This is the depth of the stack. Measure a few pieces from different spots, in inches, and use a typical one rather than the longest.
- Count the rows. For two or three rows side by side, enter the piece length and the number of rows instead of the overall depth, so the gaps between rows aren't counted as wood.
- Measure with the seller. University of Missouri Extension recommends measuring to the closest whole inch, together with the seller, while the tightly stacked wood is still on the truck. Divide inches by 12 to get feet (7 ft 6 in is 7.5 ft).
The firewood formula
The calculator runs three lines of math:
- Cubic feet = length (ft) × height (ft) × piece length (in) ÷ 12 × rows
- Cords = cubic feet ÷ 128
- Row length for one full cord = 128 ÷ (4 × piece length (in) ÷ 12)
Dividing by 12 turns the piece length from inches into feet. The 128 is the size of a cord: NIST Handbook 44, from the National Institute of Standards and Technology, lists 1 cord of firewood as exactly 128 cubic feet, which equals 8 ft × 4 ft × 4 ft. The last line tells you how long a single row 4 ft high must be to make a full cord.
Worked example (the calculator's default values)
Say you have one row of firewood 8 ft long and 4 ft high, cut into 16 in pieces.
- Piece length in feet: 16 ÷ 12 = 1.33 ft
- Volume: 8 × 4 × 16 ÷ 12 = 42.67 cu ft, shown rounded as 43 cu ft
- Cords: 42.67 ÷ 128 = 0.33 cord
- One full cord in a single 4 ft high row: 128 ÷ (4 × 16 ÷ 12) = 24.0 ft
The calculator shows the same result: "Your stack holds about 0.33 cords (43 cu ft). A full cord is 128 cu ft, for example a stack 8 ft long, 4 ft high and 4 ft deep. With 16 in pieces, one row 4 ft high has to run 24.0 ft to make a full cord."
Change the rows to 3 and the stack becomes 48 in (4 ft) deep: 8 × 4 × 16 ÷ 12 × 3 = 128 cu ft, or 1.00 cord. That is why three 8 × 4 ft rows of 16 in wood make one full cord.
The optional price field converts a quote into a price per full cord. If a seller asked $300 for the single row above (an example figure, not a market price), the calculator adds: "At $300 for this stack, that is about $900 per full cord." That makes it easy to compare sellers who stack, cut, and name their wood differently.
Firewood cord chart by piece length
Every row in this chart is 4 ft high. The numbers are straight volume math.
| Piece length | One 8 × 4 ft row | Share of a full cord | 8 × 4 ft rows per cord | Single row for 1 cord |
|---|---|---|---|---|
| 12 in | 32 cu ft | 0.25 (1/4) | 4 | 32.0 ft |
| 16 in | 43 cu ft | 0.33 (1/3) | 3 | 24.0 ft |
| 18 in | 48 cu ft | 0.38 (3/8) | 2.67 | 21.3 ft |
| 20 in | 53 cu ft | 0.42 (5/12) | 2.4 | 19.2 ft |
| 24 in | 64 cu ft | 0.50 (1/2) | 2 | 16.0 ft |
| 48 in | 128 cu ft | 1.00 | 1 | 8.0 ft |
This matches what extension services report. Penn State Extension says a face cord is generally 16 in deep and holds 1/4 to 1/2 of the wood in a cord, and Utah State University Extension puts a face cord at 32 to 48 cu ft for the usual 12 to 18 in pieces.
Cord vs. face cord, rick, and other terms
Only the cord has a fixed size. The other names describe the face of a stack, not its volume, so two sellers can use the same word for very different amounts of wood.
- Full cord: 128 cu ft, usually 8 ft long × 4 ft high × 4 ft deep.
- Half cord: 64 cu ft, which Montana State Extension describes as 4 ft deep, high, and long.
- Face cord: 4 ft high and 8 ft long, but only as deep as the pieces are long, per Utah State Extension.
- Rick or fireplace cord: often treated as one-third of a cord, though University of Kentucky forestry specialists note regional differences.
- Pile, truckload, or pickup load: Montana State Extension warns that these can vary greatly in size.
State rules vary: Connecticut as an example
Firewood sales fall under state weights and measures rules, which are not the same everywhere. Connecticut's Department of Consumer Protection publishes a clear example, taken from NIST Handbook 130:
- A cord is the amount of wood in 128 cu ft "when the wood is ranked and well stowed."
- Firewood is sold by the cord, fractions of a cord, or the cubic meter.
- The terms "face cord," "rack," "pile," "truckload," and similar terms may not be used to advertise, offer, or sell firewood.
- The delivery ticket must show the seller's and buyer's names and addresses, the delivery date, the quantity delivered, the price, and a description of the wood.
University of Missouri Extension likewise states that firewood must, by law, be sold by the cord or a fractional part of a cord, with a bill of sale. Other states may word things differently or allow terms Connecticut bans, so check with your state's weights and measures office.
How to check a delivery
- Ask before you buy for the quantity in cords, plus the stack length, height, and piece length behind it.
- Measure a tight stack. Missouri Extension advises against accepting a randomly piled load for measurement. If the wood will be dumped, agree up front that you will stack and measure it before paying.
- Compare with the ticket. Run your measurements through the calculator and keep the receipt until you have checked.
- Report a short cord to your state weights and measures office. Connecticut's DCP, for example, invites complaints about "short" cords.
Tips for seasoning and storing firewood
- Give it time. The EPA's Burn Wise program says to season wood at least six months; its firewood brochure notes softwoods take about 6 months and hardwoods about 12. Penn State Extension gives 6 to 12 months, and Missouri Extension suggests ordering in the fall for next year.
- Test it. The EPA says wood burns best below 20 percent moisture and recommends a wood moisture meter. Seasoned wood is darker, weighs less, and sounds hollow when knocked against another piece. Penn State adds small end cracks, called checks, as a sign.
- Stack for airflow. The EPA suggests a single row, split side down, on rails off the ground. Penn State recommends a dry, sunny, windy spot.
- Cover the top only. Keep the sides open. Penn State warns that wrapping the whole stack in a tarp creates a tent that holds moisture in.
- Keep it away from the house. The EPA says to build the stack away from buildings, and Missouri Extension warns that wood piled against a house can discolor it and help termites get in.
- Don't hoard it. Missouri Extension suggests not keeping wood outside more than a year or two, because borers can cut a pile's weight by 20 to 30 percent a year.
Common mistakes to avoid
- Treating a face cord as a cord. With 16 in pieces it is a third of the wood. Always ask for the piece length.
- Mixing inches and feet. The piece length field is in inches. Typing 1.33 (feet) instead of 16 gives a result twelve times too small.
- Burning it green. Missouri Extension says burning green wood can cost 10 to 12 percent of its original heat potential.
Frequently asked questions
How big is a cord of wood?
A cord is 128 cubic feet of tightly stacked wood. The classic shape is 8 ft long, 4 ft high, and 4 ft deep, but any stack that works out to 128 cu ft is a cord, such as a single row of 16 in pieces 24 ft long and 4 ft high.
What is a face cord of wood?
A stack 4 ft high and 8 ft long that is only as deep as the pieces are long, so it has no standard volume. With 16 in pieces it is about 43 cu ft, or a third of a cord; with 24 in pieces it is half a cord.
How many face cords are in a full cord?
It depends on the piece length. With 16 in pieces, three face cords make one full cord. With 12 in pieces you need four, and with 24 in pieces you need two.
How much actual wood is in a cord?
Less than 128 cubic feet, because a stack includes air between the pieces. University of Kentucky forestry specialists put the wood in a cord at about 85 cu ft.
How long does firewood need to season?
The EPA says at least six months, with softwoods taking about 6 months and hardwoods about 12. Aim for a moisture meter reading of 20 percent or less before you burn it.
Is a cord of pine worth the same as a cord of oak?
No. University of Missouri Extension notes that at 20 percent moisture, a cord of pine weighs about 2,700 pounds and a cord of oak about 3,700 pounds, so the pine has about 73 percent of the oak's potential heat. Compare prices per cord between similar species.
How big is a half cord of wood?
A half cord is 64 cubic feet. Montana State Extension describes it as 4 ft deep, 4 ft high, and 4 ft long.
What is a rick of wood?
A rick, or fireplace cord, is often treated as one-third of a cord, though University of Kentucky forestry specialists note regional differences. Like a face cord, it describes the face of a stack rather than a fixed volume, so ask for the stack length, height, and piece length.
How do I check a firewood delivery?
Ask for the quantity in cords plus the stack length, height, and piece length behind it. University of Missouri Extension advises measuring a tightly stacked load with the seller, not a random pile. Run your measurements through the calculator, compare them with the delivery ticket, and report a short cord to your state weights and measures office.
Sources
- NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement
- Connecticut Department of Consumer Protection: Firewood and Stove Wood Regulations
- University of Missouri Extension: How to Buy and Sell Firewood (G5452)
- Montana State University Extension: How Is a Cord of Firewood Measured?
- Utah State University Extension: Wood Heating
- University of Kentucky Forestry and Natural Resources: Measuring & Stacking Firewood
- Penn State Extension: Heating with Wood: An Introduction
- U.S. EPA Burn Wise: Best Wood-Burning Practices
- U.S. EPA: Burn Dry Firewood to Save Money and Health (brochure)