Board Feet Calculator
The Board Feet calculator shows the lumber volume in board feet for identical pieces and, if you add a rate, the estimated total price.
We let you enter thickness (in), width (in), length (ft), and piece count. We compute board feet using the standard formula and multiply by your quantity. Add an optional price per board foot to see a quick cost estimate for budgeting or purchase orders. If you’d rather do it by hand, we outline the formula and steps below.
Enter thickness and width in inches, length in feet, and a piece count. We multiply board feet per piece by your quantity. Add an optional price per board foot to estimate cost.
e.g., 1" (4/4), 1.5" (6/4)
Actual width (not nominal)
Board length in feet
Adds an estimated total price
Board feet = thickness (in) × width (in) × length (ft) ÷ 12. Prices vary by species, grade, and surfacing.
Results interpretation
How it works
Board feet measure lumber volume using a simple inches–inches–feet formula. We compute per piece, then multiply by your count.
Formulas, assumptions, limitations
Formula. BF = (thickness in × width in × length ft) ÷ 12.
Multiple pieces. Total BF = BF per piece × piece count.
Price (optional). Estimated price = Total BF × price per BF.
Nominal vs actual. Use actual dimensions. 2×6 is typically ~1.5 in × 5.5 in surfaced.
Rounding. We display to two decimals; you may order a bit extra for waste/defects.
Use cases & examples
Per piece: (1 × 6 × 8) ÷ 12 = 4.00 BF. Total: 4.00 × 10 = 40.00 BF. At $5.25/BF → $210.00.
Per piece: (1.5 × 9.25 × 12) ÷ 12 = 13.875 BF. Total: 13.875 × 4 = 55.50 BF.
This tool assumes identical pieces. If lengths vary, run each length separately and add the totals.
Board feet FAQs
Do I enter nominal or actual dimensions?
Enter actual finished dimensions for the most accurate result. Surfaced lumber is smaller than nominal size.
Can I price different species with one rate?
Yes—enter a blended $/BF, or compute each species separately and sum the totals.
How much overage should I order?
For projects with cuts/selection, add 5–15% depending on grade and defect tolerance.
Does moisture content affect board feet?
Board feet are geometric volume only; moisture content affects weight and movement, not the calculation.
What if I have varied thicknesses or widths?
Run a separate calculation for each unique size, then add the board-feet results.
Is price per board foot required?
No. Leave it blank to get volume only. Add it if you want a quick budget estimate.
What is a board foot?
A board foot is a unit of lumber volume equal to a board 1 inch thick, 12 inches wide, and 1 foot long. It’s convenient because most lumber is priced and quoted in board feet, even when the actual board dimensions vary.
Nominal vs. actual sizes
Sawn boards are sold by nominal size (e.g., 2×8) but finish smaller after planing. For accurate board feet and pricing, enter actual thickness and width. If in doubt, measure—common surfaced sizes include 1.5 × 5.5 in for a “2×6” and 1.5 × 9.25 in for a “2×10”.
Why contractors still use board feet
It normalizes different lengths and widths into a single comparable number that aligns with mill production and wholesale pricing. It also makes estimating fast—volume first, then multiply by a current price per board foot.
Practical ordering tips
- Group your list by identical dimensions to avoid mistakes.
- Add waste for trimming ends, matching grain/color, and cutting around defects.
- Ask suppliers for surfaced (S4S) vs. rough thickness so you can enter the right numbers.
- Species, grade, and moisture affect price—keep your $/BF assumption documented.
From plan to purchase order
Once you have total board feet, share the calculation and assumptions with your supplier. Our copy link helps keep your numbers consistent as specifications change.