Board Foot Calculator
Calculate board feet for hardwood, softwood, and logs — then see cost and shipping weight. Built around how lumber yards actually charge, so there are no surprises at the counter.
What does a board foot actually measure?
A board foot is a unit of volume equal to 144 cubic inches — a piece 12 inches wide, 12 inches long, and 1 inch thick. Because it includes thickness, it is not the same as square feet (area) or linear feet (length). The formula every yard uses:
Board feet = Thickness(in) × Width(in) × Length(ft) ÷ 12
If you want the full walkthrough with worked examples, read how to calculate board feet, or learn what a board foot is from the ground up. Prefer to browse? Every calculator and guide is grouped by job in the full guide directory.
Calculators for every job
Which board foot calculator should you use?
Hardwood Calculator
Actual dimensions, 4/4–12/4 quarter sizing, and NHLA thickness rounding for dealer-bought stock.
Open hardwood mode →Log Calculator
Estimate lumber yield from logs with the Doyle, Scribner and International ¼-inch rules.
Scale a log →Lumber Cost Calculator
Turn board feet into a budget using price per board foot for any species.
Estimate cost →Cut List Calculator
Add up a whole project — up to 30 boards, multiple species, CSV export.
Build a cut list →Spray Foam Calculator
Different math entirely — area × thickness for insulation board feet of coverage.
Estimate foam →BF ↔ SF Converter
Convert between board feet and square feet without guessing the thickness.
Convert →What are the most common board foot sizes?
Nominal board feet for standard softwood sizes by length. Bookmark the full board foot cheat sheet for printing.
| Size | 6 ft | 8 ft | 10 ft | 12 ft | 16 ft |
|---|---|---|---|---|---|
| 2×4 | 4.00 | 5.33 | 6.67 | 8.00 | 10.67 |
| 2×6 | 6.00 | 8.00 | 10.00 | 12.00 | 16.00 |
| 2×8 | 8.00 | 10.67 | 13.33 | 16.00 | 21.33 |
| 2×10 | 10.00 | 13.33 | 16.67 | 20.00 | 26.67 |
| 2×12 | 12.00 | 16.00 | 20.00 | 24.00 | 32.00 |
| 4×4 | 8.00 | 10.67 | 13.33 | 16.00 | 21.33 |
Want a single board answer? See how many board feet in a 2×4, a 2×6, or a 2×8.
Buy lumber without getting burned
What rules does the lumber yard play by?
Nominal vs Actual
Why a 2×4 is really 1.5″ × 3.5″ — and when each size is used for pricing.
Gross vs Net Tally
How an 8–10% tally difference can quietly inflate your invoice.
Waste Factor Guide
Exactly how much extra to buy by project type, so you never run short.
4/4, 5/4, 6/4, 8/4 Guide
Decode quarter thickness and how dealers round it when billing.
Why You Got Charged More
The common reasons your bill beats your own measurement.
How to Buy by Board Foot
A buyer's checklist for verifying a hardwood tally before you pay.
Frequently asked questions
What is a board foot?
A board foot is a unit of lumber volume equal to 144 cubic inches — for example a piece 12″ wide, 12″ long and 1″ thick. It measures volume, not surface area, which is why it differs from square feet and linear feet.
How do you calculate board feet?
Multiply thickness (inches) × width (inches) × length (feet), then divide by 12. A 1″ × 6″ × 8 ft board is (1 × 6 × 8) ÷ 12 = 4 board feet. Full method: how to calculate board feet.
How many board feet are in a 2×4?
A nominal 2×4 holds about 0.667 BF per linear foot, so an 8-ft 2×4 = 5.33 BF and a 10-ft 2×4 = 6.67 BF. See the breakdown at how many board feet in a 2×4.
Why do board foot calculators give different results?
Because of nominal versus actual dimensions, thickness rounding rules, and waste assumptions. We explain every difference in why calculators disagree.
Is lumber sold by nominal or actual size?
Softwood is priced by nominal size; hardwood is priced by actual measured size, usually with thickness rounded up to the nearest quarter inch. More: nominal vs actual dimensions.
How much waste should I add?
15–20% for FAS hardwood with simple cuts, 25–35% for rough sawn, and 10–15% for flooring. See the waste factor guide.
How do I figure cost per board foot?
Multiply total board feet × price per board foot. For 20 BF of walnut at $13/BF, cost = $260. The lumber cost calculator does it instantly.
Does the calculator work offline?
Yes — it is a progressive web app that saves your cut list locally and keeps working with no signal, so you can use it at the yard.