A cord of wood calculator helps you measure firewood stacks accurately, compare heat output by species, and decide whether wood heating is cost-effective for your home. One cord is a tightly stacked pile measuring 4 ft × 4 ft × 8 ft (128 cubic feet), but BTU output varies dramatically by species — knowing the difference can save hundreds of dollars per heating season.
Measure Your Wood Stack
Log length. 16" = 1.33 ft
BTU & Cost Comparison by Species
Same price assumed for comparison
Cord Size Quick Reference
| Unit | Dimensions | Stacked Cu Ft | Fraction of Cord |
|---|---|---|---|
| Full cord | 4 ft × 4 ft × 8 ft | 128 | 1.00 |
| Face cord (rick) | 4 ft × 8 ft × 16 in | 42.7 | 1/3 |
| Half cord | 4 ft × 4 ft × 4 ft | 64 | 1/2 |
| Quarter cord | 4 ft × 2 ft × 4 ft | 32 | 1/4 |
How to Use the Cord of Wood Calculator
Buying firewood without knowing exactly how much you have — or how much heat it will produce — can leave you short in mid-January or overpaying for low-BTU softwood. This free cord of wood calculator tells you the exact volume of any stack, the BTU output for your chosen species, and how your heating cost compares to oil, gas, or electric.
Step 1: Measure Your Stack or Enter Cords
Use the Stack Dimensions method to measure an existing or planned woodpile. Enter the length, height, and depth of the stack in feet. The depth is the log length — 16-inch logs are 1.33 feet deep, 24-inch logs are 2 feet deep. If you already know how many cords you have (for example, your supplier quoted "2.5 cords"), switch to the Number of Cords method and enter it directly.
Step 2: Choose Your Wood Species
Select the species from the dropdown. Dense hardwoods like hickory (30.6 million BTU/cord), white oak (29.1 million BTU/cord), and sugar maple (29.0 million BTU/cord) deliver the most heat per cord and are ideal for home heating. Softwoods like cedar (13.0 million BTU/cord) and white pine (15.9 million BTU/cord) burn faster and produce significantly less heat — they are better for kindling or mild shoulder-season fires.
Step 3: Add Your Cost Per Cord
Enter what you paid (or were quoted) per full cord. The calculator converts this into a cost per million BTU, which lets you compare wood heating against other fuels on a true apples-to-apples basis. A cord of white oak at $300 works out to roughly $10.31 per million BTU — often cheaper than heating oil or electric resistance heat, but the comparison shifts with local fuel prices.
Step 4: Compare All Species at Once
Switch to the BTU & Cost Comparison tab to see all 12 species ranked by heat output. Enter the number of cords and a single price per cord, and the table shows total BTU and cost per million BTU for every species. This helps you decide whether a cheaper load of ash is a better deal than premium hickory, or understand the real cost difference when a supplier quotes different species.
Understanding Face Cords vs Full Cords
A face cord (also called a rick or stove cord) looks the same width and height as a full cord — 4 ft tall × 8 ft wide — but the logs are only 16 inches deep instead of 4 feet. That means a face cord is only about one-third of a full cord (128 cu ft). Always confirm the log length before you buy. If a seller quotes a price per "cord" but delivers 16-inch logs stacked 4 ft × 8 ft, you are receiving a face cord. The quick reference table below the calculator shows the dimensions and cubic footage for each unit.
Tips for Accurate Measurement
Stack the wood tightly in a straight row before measuring — loose or rounded piles contain more air. Measure height at the average point, not the tallest log. Green (freshly cut) wood holds 20–25% more water weight and produces significantly less usable heat than seasoned wood dried for at least 6–12 months. The BTU values in this firewood calculator assume properly seasoned wood.
FAQ
Is this cord of wood calculator free?
Yes, the firewood calculator is completely free with no limits. Calculate as many stacks as you need, compare any species, and estimate heating costs. No signup or account is required — everything runs locally in your browser.
Is my data private?
Yes. All calculations run entirely in your browser. Your stack dimensions, species choices, and cost figures are never sent to any server. No data ever leaves your device.
How many cubic feet are in a cord of wood?
A full cord of wood is exactly 128 cubic feet when the logs are stacked (4 ft wide × 4 ft tall × 8 ft long). The solid wood content is typically 80–100 cubic feet because air fills the gaps between logs. A face cord is one-third of a full cord, measuring 4 ft × 8 ft × 16 inches deep.
What is the difference between a cord and a face cord?
A full cord is 4 feet wide, 4 feet tall, and 8 feet long (128 cubic feet stacked). A face cord is also 4 feet tall and 8 feet long but only 16 inches deep — about one-third of a full cord. Some sellers call face cords 'ricks' or 'stove cords.' Always confirm the actual dimensions before buying firewood.
Which firewood species produces the most heat?
Hickory produces the most heat at about 30.6 million BTU per cord, followed closely by white oak (29.1 million BTU) and sugar maple (29.0 million BTU). Softwoods like cedar (13 million BTU) and white pine (15.9 million BTU) produce significantly less heat per cord and burn faster. Hardwoods are generally far better for home heating.
How does firewood compare to heating oil or natural gas?
A cord of white oak (29.1 million BTU) is equivalent to roughly 213 gallons of heating oil or 291 therms of natural gas. Actual heating efficiency varies because wood stoves and furnaces have different combustion efficiencies. The calculator uses standard BTU content values; your real-world savings depend on your heating system's efficiency rating.
How do I measure a cord of wood myself?
Stack the logs neatly in a row, then measure the total length, height, and depth of the stack in feet. Multiply all three dimensions: length × height × depth. Divide by 128 to get full cords. For example, a stack 8 ft long × 4 ft tall × 4 ft deep = 128 ÷ 128 = 1 full cord.
How much wood do I need to heat my home for the winter?
A well-insulated 1,500 sq ft home in a cold climate typically needs 3–5 cords of hardwood per heating season. Larger or poorly insulated homes may need 6–10 cords. Your actual consumption depends on your climate zone, how often you use supplemental heating, and the efficiency of your wood stove or fireplace insert.