Lumber Calculator
Work out board feet, linear feet and cost for your lumber — add each size, length and quantity to a running list and get the totals. Pick a nominal size (2×4, 2×6, 4×4…) or enter custom dimensions, add a price per board foot for the cost, and send it to a quote. Works in feet (metres). Everything runs on your device.
Guide: How Do I Calculate Board Feet?Lumber piece
Lumber list
Build your order: set a size, length and quantity above and press Add to list. The totals below sum the board feet, linear length and cost across every line.
Nominal size, no waste added
Board feet use the nominal size — a “2×” counts as 2 in even though it's dressed to 1½ in — which is how softwood is billed. For rough-sawn or hardwood sold by the board foot, enter the actual measured size. No cut waste is added; allow extra on your quantities for offcuts and defects.
Questions & answers
Everything you need to understand the lumber calculator.
How do I calculate board feet?
A board foot is a piece 1 in thick × 12 in wide × 1 ft long (144 cubic inches). Board feet = (thickness in × width in × length ft) ÷ 12. A 2×4 that is 8 ft long is (2 × 4 × 8) ÷ 12 = 5.33 board feet. Enter the size, length and quantity and the calculator totals the board feet across your whole list.
Do I use the nominal or the actual size for board feet?
For dressed softwood (framing lumber), board feet use the nominal size — a 2×4 counts as 2 in by 4 in even though it is actually 1½ × 3½ in, because that is how it is sold. For rough-sawn or hardwood lumber priced by the board foot, use the actual measured thickness and width. The calculator’s size presets are nominal; switch to custom for rough stock.
How do I convert linear feet to board feet?
Board feet = linear feet × (nominal thickness in × nominal width in ÷ 12). So 100 linear feet of 2×6 is 100 × (2 × 6 ÷ 12) = 100 board feet; the same 100 ft of 2×4 is 100 × (8 ÷ 12) = 67 board feet. Enter your size and total length and the calculator does the conversion.
How much does lumber cost per board foot?
It varies widely by species and grade — construction softwood is often a few dollars per board foot, while hardwoods run much higher. Enter your price per board foot and the calculator multiplies it by the total board feet for a material cost. Note that dimensional studs are frequently priced per piece rather than per board foot.
How many board feet are in a 2×4?
A 2×4 holds 0.667 board feet per linear foot (2 × 4 ÷ 12). So an 8 ft 2×4 is 5.33 board feet, a 10 ft is 6.67, and a 12 ft is 8. Multiply by how many you need — the calculator keeps the running total for a full pack.
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