What is a cord of firewood?
A cord is defined in law, not by custom. The federal standard adopted by most states says a cord is the amount of wood contained in a space of 128 cubic feet when the wood is ranked and well stowed, and it spells out what that means: “pieces of wood are placed in a line or row, with individual pieces touching and parallel to each other, and stacked in a compact manner.”
That last part matters. Wood thrown in a criss-cross or log-cabin pile stands up nicely and looks generous, but it holds less wood than the same space stacked parallel — and it does not meet the definition.
How many cubic feet are in a cord of firewood?
A cord is 128 cubic feet of stacked wood, bark and air: a pile 4 ft high, 8 ft long and 4 ft deep, or any other shape with the same volume. That is about 3.62 cubic metres, or 4.74 cubic yards. Only part of it is wood. The published heat tables assume roughly 70 cubic feet of solid wood per cord, and Minnesota, which allows firewood to be sold by weight, converts at 79 cubic feet of solid wood per cord. The rest is the air between the pieces. In cubic yards, those 70 to 79 ft³ of solid wood are about 2.6 to 2.9 yd³.
| Amount | Stacked volume | Typical stack (4 ft high × 8 ft long) |
|---|---|---|
| 1 cord | 128 ft³ (3.62 m³) | 4 ft deep (three rows of 16-inch pieces) |
| 1/2 cord | 64 ft³ | 24-inch pieces, one row |
| 1/3 cord | 42.7 ft³ | 16-inch pieces, one row (often sold as a “face cord”) |
| 1/4 cord | 32 ft³ | 12-inch pieces, one row |
To check a delivery, multiply height × length × piece length in feet and divide by 128. A stack 4 ft high, 10 ft long with 16-inch pieces is 4 × 10 × 1.33 = 53.3 ft³, or 0.42 of a cord. The calculator above does this for any stack, and the Face Cord Calculator handles single rows sold by the face.
Is a “face cord” a legal way to sell firewood?
No. The regulation is explicit: “The terms ‘face cord,’ ‘rack,’ ‘pile,’ ‘truckload,’ or terms of similar import shall not be used when advertising, offering for sale, or selling wood for use as fuel.” Firewood must be sold by the cord, by a fraction of a cord, or by the cubic metre.
The reason is simple: a “face cord” describes the face of a stack — its height and length — and says nothing about how deep it is. A 4 ft × 8 ft face of 12-inch pieces is a quarter of a cord. The same face in 24-inch pieces is half a cord. Same name, twice the wood. If you were quoted by the face cord, the Face Cord Calculator turns that price into a price per full cord, and the Cord of Wood Price page sets it against the one official price series we found.
What am I entitled to when firewood is delivered?
For any firewood that is not pre-packaged, the seller must hand you a delivery ticket or sales invoice showing:
- the name and address of the seller;
- your name and address;
- the date of delivery;
- the quantity delivered, and the quantity the price is based on if they differ;
- the price.
If the load is sold as a species mix, the declaration has to be accurate to within 10 %.
That text is the uniform regulation most states adopt as their own. Which office enforces it where you live, what your state lets a seller write instead, and the order to follow when a delivery looks short are on firewood sale law, state by state.
How do I work out the real cost per cord?
Divide what you paid by the fraction of a cord you actually received. That second number is the one sellers rarely give you, and it is where the money hides: a pile sold at $250 that measures a third of a cord costs $750 per cord, whatever the advertisement said.
Comparing two quotes only means something once both are expressed per cord. Two deliveries at the same price can differ by a factor of three, and nothing on the invoice will say so unless you ask for the volume.
How much heat is in a cord?
Pound for pound, every species of wood carries about the same energy — roughly 8,600 BTU per pound of ovendry wood. Oak does not burn hotter than pine because it is better wood; it burns longer because a cubic foot of oak simply contains more wood.
So heat per cord follows density, and the calculation is:
MBTU per cord = solid ft³ × specific gravity × 62.4 lb/ft³ × 8,600 BTU/lb ÷ 1,000,000
The Firewood BTU Chart applies that formula to all 146 species, softwoods included, and lets you sort and filter them.
Why do published BTU tables disagree by half?
Because they measure two different things, and rarely say which.
- Energy contained — what is in the wood. Penn State Extension lists red oak at 24 million BTU per cord on this basis.
- Heat delivered — what reaches the room after the stove wastes the rest. The University of Arkansas lists the same red oak at 12.2 million BTU, because it applies a 50 % burning efficiency.
Neither is wrong. But a page that copies one figure without naming the basis is out by a factor of two. This calculator shows both, and lets you set your own appliance efficiency.
Why two identical cords can hold different amounts of wood
A cord is 128 cubic feet of wood, bark and air. How much of that is wood depends on how the pieces are shaped and stacked. Working backwards from the published heat tables, they all assume about 70 cubic feet of solid wood in a cord — roughly 55 % wood, 45 % air.
Nobody writes that number down, yet it decides the answer. Round unsplit rounds, short pieces, crooked pieces and loose stacking all reduce it. A cord stacked at 55 ft³ of solid wood holds a fifth less fuel than one at 70 — for the same price. That is why the assumption is an input on this page instead of a constant buried in the code.
How reliable are the figures for pine, spruce and fir?
Less certain than the ones for hardwoods, and it is worth knowing why. The heat calculation is checked against the published Penn State table for eight hardwood species and lands within 8 % each time. But the reference tables we check against cover hardwoods only. Softwood values do circulate on other websites, but we have not found one that states a traceable method, so there is nothing independent to check ours against.
Softwood figures here are produced by the same formula from the same official densities, so they are consistent with the hardwood results rather than guessed. They are simply not confirmed against an independent source, because there is none to confirm them against. Treat them as sound estimates, not as published values.
How much does a cord weigh?
Enough to matter for whoever is moving it. Weight depends on species and, far more than most people expect, on whether the wood is green. Freshly cut wood can carry more water than wood — the sapwood of some pines holds over twice its own dry weight in water.
As an order of magnitude, a seasoned cord of hardwood weighs about 3,000 to 3,400 lb and a green one about 3,900 to 4,400 lb, depending on how tightly it is stacked. The Cord of Wood Weight Calculator gives the figure for each of the 146 species, for a face cord or any stacked volume, the water a green load will lose, and how many trips your vehicle needs.
Frequently asked questions
How many cubic feet of actual wood are in a cord?
Less than the 128 ft³ of the stack. Heat tables assume about 70 ft³ of solid wood, and Minnesota converts weight sales at 79 ft³ per cord. Round unsplit pieces, crooked wood and loose stacking can bring it closer to 55 ft³ — which is why the solid-wood figure is an input on this page.
Is a pickup truck load a cord?
Almost never, and “truckload” is not a legal unit. A long bed is about 4 ft × 8 ft, so filling it level to 4 ft would be a cord — but few beds are 4 ft deep and few loads are stacked. Measure the stack after it is unloaded.
My pieces are 16 inches. How many stacks make a cord?
Three. Three rows of 16-inch pieces make 48 inches of depth, which with a 4 ft × 8 ft face gives the 128 cubic feet.
Does bark count toward the cord?
Yes, twice over. The legal definition counts wood, bark and air together, and the published heat tables are measured on wood and bark — the Arkansas figures state it explicitly. So the heat shown here includes the bark, and the bark row is there to tell you how much of the pile it represents: 4 % to 20 % of the volume depending on species. Bark carries about 87 % of the heat per pound that wood does.
Is seasoned wood worth more than green wood?
For burning, yes — green wood spends a large share of its energy evaporating its own water. For volume, no: a cord is a cord whether it is wet or dry.
What if the seller refuses to give me an invoice?
The delivery ticket is required for any non-packaged firewood sale. Your state weights and measures office enforces this; several publish firewood complaint procedures.
Sources
- NIST Handbook 130-2023, Uniform Regulation for the Method of Sale of Commodities, section 2.4 “Fireplace and Stove Wood” — the cord definition, the permitted units, the prohibited terms and the delivery ticket.
- Washington State Department of Agriculture — how the rule is applied and enforced, including why criss-cross stacking does not qualify.
- University of Arkansas Extension FSA-1091, Basics of Heating with Firewood — 8,600 BTU per pound ovendry, available heat at 20 % moisture, and the 50 % efficiency basis.
- Penn State Extension, Heating with Wood: An Introduction — energy per cord by species.
- Miles & Smith (2009), USDA Forest Service Research Note NRS-38 — specific gravity, moisture content, green weight and bark percentage for 156 North American species. The species data on this page comes from its Table 1A.