How it works
Firewood is sold by stacked volume. A full cord is a tightly stacked pile 4 ft high, 4 ft deep and 8 ft long, which is 128 cubic feet including the air gaps between logs. A face cord is a single row 4 ft high and 8 ft long, as deep as one log is long. In metric countries firewood is often sold by the stacked cubic meter, called a stere.
stacked volume (cu ft) = length (ft) × height (ft) × depth (in) ÷ 12
cords = volume ÷ 128 · face cords = volume ÷ (32 × log length in ÷ 12) · m³ = cu ft × 0.0283
Worked example
A single row of 16 in logs stacked 24 ft long and 4 ft high is 24 × 4 × 16 ÷ 12 = 128 cu ft. That is exactly 1 full cord, 3 face cords, or 3.62 m³ stacked.
A shorter row, 20 ft long and 4 ft high with the same 16 in logs, holds 106.7 cu ft: 0.83 cords, 2.5 face cords or 3.02 m³. If you were promised a cord, you are about one sixth short.
Face cord size by log length
| Log length | Face cord volume | Share of a full cord |
|---|---|---|
| 12 in (30 cm) | 32 cu ft | 1/4 (0.25) |
| 16 in (41 cm) | 42.7 cu ft | 1/3 (0.33) |
| 18 in (46 cm) | 48 cu ft | 3/8 (0.375) |
| 24 in (61 cm) | 64 cu ft | 1/2 (0.5) |
Because a face cord depends on log length, two sellers can both advertise a face cord and deliver very different amounts. Ask for the log length, or compare prices per full cord. Put the price in the calculator to see what the pile in front of you is worth.
Measuring a pile
- Stack the wood tightly with logs parallel before measuring. Gaps from crooked or loosely thrown pieces inflate the volume.
- Measure the height at several points along the stack and use the average. Piles often sag at the ends.
- Measure depth as the length of a typical log for a single row. For a stack two rows deep, measure the full depth.
- For round or uneven piles, rough out the dimensions in rectangles and add them up.
Unit conversions
| Unit | Cubic feet | Cubic meters |
|---|---|---|
| Full cord | 128 | 3.62 |
| Stere (1 m³ stacked) | 35.3 | 1 |
| Face cord, 16 in logs | 42.7 | 1.21 |
In Australia firewood is commonly sold by the tonne. Weight depends on species and moisture, so ask the seller how dry the wood is. Wet wood weighs more and gives less heat.
How much wood do you need for a winter?
There is no single answer. It depends on whether wood is your main heat or an occasional fire, how cold your winter is, how well the house is insulated, the species and dryness of the wood and how efficient your stove or fireplace is. Open fireplaces send much of their heat up the chimney, while modern certified stoves burn far more completely. The best guide is your own record: measure the stack at the start of the season with this calculator, measure again at the end and you will know what a winter takes in your home.
Burning and storing wood safely
- Burn only seasoned wood. A moisture meter should read below 20 percent. Wet wood smokes, wastes heat and builds creosote in the chimney.
- Stack wood off the ground with the top covered and the sides open to the wind.
- Keep stacks away from the house walls to reduce fire risk and pests. Many fire services suggest at least 30 ft (9 m) in wildfire-prone areas.
- Have the chimney inspected yearly, and keep working smoke and carbon monoxide alarms in the home.
- Moving firewood can spread invasive insects. Buy it locally where you will burn it, and follow any local firewood rules.
Frequently asked questions
How many face cords are in a full cord?
It depends on log length. With 16 in logs there are 3 face cords in a cord, with 12 in logs there are 4, and with 24 in logs there are 2.
What are the dimensions of a cord of wood?
4 ft high, 4 ft deep and 8 ft long when tightly stacked, a total of 128 cubic feet or about 3.62 cubic meters.
What is a stere of firewood?
A stere is one cubic meter of stacked wood, about 35.3 cubic feet, or 0.28 of a full cord.