Calculate-Compare-Decide
Turn any wood stack into full cords, face cords, ricks, cubic feet and cubic meters — then see its weight, heat output in BTU, how long it will heat your home, and whether the price you were quoted is fair.
Heat load is an estimate from home size and climate — actual use depends on insulation and habits.
Your selection is highlighted. A cord of oak carries nearly twice the heat of a cord of pine — at similar prices, that's the real bargain.
A firewood calculator estimates how much wood you have or need from stack dimensions and log length. It converts the stack into full cords, face cords, ricks, cubic feet and cubic meters, and can also estimate weight, heat output in BTU, how many days it will heat your home, and total cost.
A full cord is 4 ft high × 4 ft deep × 8 ft long = 128 cubic feet of stacked wood. A face cord is 4 ft × 8 ft but only one log deep, so with 16" logs it's just ⅓ of a full cord (42.7 ft³). Only the full cord is legally defined.
Worked example — an 8 ft × 4 ft stack of 16″ logs. Convert the log length: 16 ÷ 12 = 1.333 ft. Volume = 8 × 4 × 1.333 = 42.7 ft³. Divide by 128 → 0.33 cords. That is exactly one face cord — and precisely one third of a full cord, not a third of the price if you're not careful.
This is where money is lost. A "face cord" of 16″ logs is ⅓ of a cord. A "face cord" of 24″ logs is ½ a cord — 50% more wood for the same name. Sellers aren't necessarily dishonest; the term simply isn't standardized. Always ask the log length, then convert to full cords before comparing any two prices.
Species matters as much as volume. A cord of white oak delivers about 29 million BTU; a cord of pine about 15.9 million. If oak costs $250 and pine costs $200, the oak is cheaper per unit of heat — $8.60 per million BTU versus $12.60.
| Species | Million BTU / cord | lb / cord (seasoned) | Notes |
|---|---|---|---|
| White oak | 29.1 | 4,200 | Top-tier heat, long burn, slow to season |
| Hickory | 27.7 | 4,300 | Excellent heat, heaviest, great coals |
| Beech | 27.5 | 3,800 | Superb heat, needs long seasoning |
| Red oak | 24.6 | 3,700 | The benchmark firewood; season 12+ months |
| Ash | 24.2 | 3,500 | Splits easily, seasons fast — a favourite |
| Sugar maple | 24.0 | 3,700 | Steady heat, clean burn |
| Black walnut | 22.2 | 3,200 | Good heat, pleasant aroma |
| Cherry | 20.4 | 2,900 | Moderate heat, lovely scent |
| Birch | 20.3 | 3,200 | Burns fast, rots quickly if not stacked dry |
| Douglas fir | 20.7 | 2,400 | Best of the softwoods |
| Pine | 15.9 | 2,200 | Fast, hot, smoky — fine kindling, poor overnight |
| Spruce | 15.5 | 2,100 | Low heat, sparks |
| Cedar | 13.0 | 2,000 | Great kindling, poor primary fuel |
| Log length | Fraction of cord | ft³ |
|---|---|---|
| 12 in | 1/4 (0.25) | 32 |
| 14 in | 0.29 | 37.3 |
| 16 in (typical) | 1/3 (0.33) | 42.7 |
| 18 in | 0.375 | 48 |
| 20 in | 0.42 | 53.3 |
| 24 in | 1/2 (0.50) | 64 |
| State | Moisture | Usable heat |
|---|---|---|
| Green (fresh cut) | 50%+ | ~65% |
| Seasoned | ~20% | 100% |
| Kiln-dried | <15% | ~105% |
| Appliance | Efficiency |
|---|---|
| Open fireplace | ~15% |
| Fireplace insert | ~55% |
| Wood stove | ~70% |
| Wood furnace | ~75% |
| High-efficiency stove | ~80% |
| Unit | Cubic feet | Cubic meters | Full cords |
|---|---|---|---|
| Full cord (4×4×8) | 128 | 3.62 | 1.00 |
| Face cord (16″ logs) | 42.7 | 1.21 | 0.33 |
| Rick (= face cord) | varies | varies | varies |
| Half cord | 64 | 1.81 | 0.50 |
| Pickup bed (8 ft, level) | ~64 | ~1.81 | ~0.50 |
| Pickup bed (6 ft, level) | ~40 | ~1.13 | ~0.31 |
1.00 cord · 128 ft³ · 3 face cords of 16″ logs
0.33 cords · 42.7 ft³ · a third of a cord
0.50 cords · 64 ft³ — always ask the log length
24.6M BTU · 3,700 lb · ~98 heating days in a stove
15.9M BTU · 2,200 lb · 35% less heat than oak
16.0M BTU usable · weighs 6,475 lb · 35% wasted
~4.6 cords of seasoned oak in a 70% wood stove
~21 cords — at 15% efficiency, most heat goes up the flue
A full cord is a stack 4 feet high, 4 feet deep and 8 feet long — 128 cubic feet of wood including the air gaps between the pieces. In most US states it is the only firewood measurement defined in law, which is exactly why it's the one to insist on. Every other term you'll hear at the roadside is a regional custom, not a standard.
A face cord (often called a rick) is 4 feet high and 8 feet long — but only one log deep. That's the catch: its volume depends entirely on how long the logs are. With 16-inch logs, a face cord is 42.7 cubic feet, or one third of a full cord. With 24-inch logs it's half a cord — the same words describing 50% more wood.
So when someone advertises "a cord" for a suspiciously good price, ask one question: are those 4-foot-deep stacks, or face cords? And if it's a face cord, how long are the logs? A $150 "cord" that turns out to be a face cord of 16″ logs is really $450 per full cord — far above market. The calculator above converts any stack to full cords precisely so you can make that comparison in seconds.
Wood is bought by volume but burned for heat, and the two diverge sharply. A cord of white oak yields roughly 29 million BTU; a cord of pine about 15.9 million — nearly half. Dense hardwoods (oak, hickory, beech, ash, maple) burn longer, produce better coals and hold a fire overnight. Softwoods (pine, spruce, cedar, fir) light easily and burn fast, which makes them excellent kindling and poor primary fuel.
The practical test isn't price per cord, it's price per million BTU. Oak at $250 a cord costs about $8.60 per million BTU. Pine at $200 costs $12.60. The "cheaper" wood is the more expensive heat.
Freshly cut green wood can be over 50% water by weight. Burning it means spending a large share of the fire's energy boiling that water away before any heat reaches the room — roughly 35% of the usable heat is lost. It also burns cool and smoky, which coats your chimney in creosote and creates a genuine fire risk.
Seasoned wood has been split, stacked and air-dried for six to twelve months (oak wants a full year or more) down to about 20% moisture. Kiln-dried is taken below 15% — it lights instantly, burns hottest and cleanest, and costs a premium. For most people, properly seasoned wood is the sweet spot; the real error is buying "seasoned" wood that isn't. A moisture meter costs less than a single bad cord.
Seasoned wood is noticeably lighter, has darkened, cracked ends, and the bark loosens or falls away. Knock two pieces together: dry wood clacks, wet wood gives a dull thud. A moisture meter on a freshly split face should read under 20%. Wood delivered "seasoned" in autumn that was standing timber in summer is not seasoned, whatever the invoice says.
A typical well-insulated home using a modern stove as its main heat source burns somewhere between 3 and 5 cords a season, but the range is enormous — it depends on floor area, climate, insulation, how warm you keep the house, and above all the efficiency of your appliance. This is the number people underestimate most: an open fireplace runs around 15% efficient, meaning 85% of your wood's heat disappears up the chimney. A modern stove is 70–80%. Switching appliance can cut your wood consumption by a factor of four or five for the same warmth. The planner in advanced mode estimates your season from home size, climate, appliance and season length.
Get the wood off the ground on pallets or rails, stack it in single rows so air can move through, and cover only the top — wrapping the sides traps moisture and prevents drying. A sunny, breezy spot beats a dark shed. Split before stacking, because wood dries through the exposed faces, not the bark. And stack it the season before you need it: nothing seasons wood like time.
The recurring ones: paying cord prices for face cords, not asking the log length, buying "seasoned" wood without checking moisture, burning softwood as primary fuel and wondering why the house is cold, stacking against a wall with no airflow, covering the whole pile with a tarp, and heating with an open fireplace while assuming it's saving money. Each one is easy to avoid once you know the number to ask for — and now you can calculate it.
A firewood calculator estimates how much wood you have or need based on stack dimensions and log length. It converts the stack into full cords, face cords, ricks, cubic feet and cubic meters, and can also estimate weight, heat output in BTU, how many days it will heat your home, and total cost.
A full cord is a stack measuring 4 feet high by 4 feet deep by 8 feet long, which equals 128 cubic feet of stacked wood including the air gaps. This is the only legally defined firewood measurement in most US states. Any other term, such as face cord or rick, is not standardized.
A face cord is 4 feet high by 8 feet long, but only one log deep, so its size depends entirely on the log length. With 16 inch logs it is about 42.7 cubic feet, or one third of a full cord. With 24 inch logs it is half a cord. Always ask for the log length before agreeing a price.
A rick is generally the same as a face cord, a stack 4 feet high and 8 feet long with the depth set by the log length. It is not a standardized measurement, so its volume varies by seller and region. Always confirm the log length and convert to full cords before comparing prices.
It depends on log length. With 16 inch logs, three face cords make one full cord. With 12 inch logs it takes four, and with 24 inch logs only two. This is why buying by the face cord can be misleading, and why converting to full cords is the only fair way to compare prices.
Dense hardwoods produce the most heat per cord. White oak is around 29 million BTU per cord, hickory about 27.7 and beech about 27.5. Softwoods are much lower: pine is about 15.9 million and cedar about 13. Roughly speaking, a cord of oak delivers nearly twice the heat of a cord of pine.
Green wood is freshly cut with high moisture, so much of its energy is wasted boiling off water, delivering roughly 35 percent less usable heat while producing more smoke and creosote. Seasoned wood has dried for six to twelve months to about 20 percent moisture. Kiln-dried wood is under 15 percent and burns hottest and cleanest.
No. It provides estimates. Stacked wood volume includes air gaps that vary with how tightly the wood is piled and how straight the pieces are, and BTU, weight and moisture figures are typical values that differ by tree, region and drying conditions. Use it for planning and price comparison, not exact measurement.
Most homes heating primarily with wood burn 3 to 5 cords per season, but it varies widely with home size, climate, insulation and appliance efficiency. A modern stove at 70 percent efficiency might need 4 cords where an open fireplace at 15 percent would need over 20. The planner in advanced mode estimates your figure.
Most species need 6 to 12 months split and stacked in a dry, airy spot. Dense woods like oak often want a full year or more, while ash and softwoods can be ready in about 6 months. Split the wood first, since it dries through the exposed faces rather than the bark, and stack it a season ahead of when you need it.
It depends on species and moisture. Seasoned red oak runs about 3,700 pounds per cord and hickory about 4,300, while pine is nearer 2,200. Green wood is dramatically heavier because of its water content, often around 75 percent more, so a green cord of oak can approach 6,500 pounds. Check your trailer's rating before hauling.
Seasoned wood is lighter, has darkened and cracked ends, and its bark often loosens. Knocked together, two dry pieces make a sharp clack rather than a dull thud. The reliable test is a moisture meter on a freshly split face, which should read under 20 percent. Do not rely on a seller's word alone.
Compare price per million BTU, not price per cord. Oak at 250 dollars a cord delivers about 24 to 29 million BTU, roughly 8.60 dollars per million. Pine at 200 dollars delivers about 15.9 million, roughly 12.60 dollars per million. The cheaper cord is often the more expensive heat, so oak usually wins on value.
You can, but you should not. Green wood wastes roughly a third of its energy evaporating water, burns cool and smoky, and deposits creosote in the chimney, which is a leading cause of chimney fires. It is also harder to light and keep going. Season the wood properly, or buy kiln-dried if you need it immediately.
Yes. The share button copies a link that encodes your stack dimensions, species, moisture and prices, so you can revisit it or send it to a supplier. You can also print or save the estimate as a PDF. Everything runs in your browser and nothing is uploaded or stored on a server.