Board Foot Calculator

Enter the thickness, width, and length of one board, then how many pieces you are buying. In the default US mode, put thickness and width in inches and length in feet — that matches how lumber is labeled (a "2x6x8" is 2 in thick, 6 in wide, 8 ft long). Hit calculate and you get the total board feet instantly. Need the bill? Open More options, switch to metric if your boards are metric-sized, or add a price per board foot to see total lumber cost.

A board foot is a unit of *volume* used to sell hardwood and rough lumber, not a unit of length. One board foot equals a piece 1 inch thick, 12 inches wide, and 12 inches long — exactly 144 cubic inches. Because it measures volume, a thick board racks up board feet fast: a 2x6x8 holds 8 board feet, while a 1x6x8 of the same footprint holds only 4. That is why lumber yards quote hardwood "per board foot" rather than per plank — it prices the actual wood you take home, regardless of how the mill cut it. This is also why a board foot calculator beats guessing: the math is easy to get wrong when thickness is in inches but length is in feet.

Board feet = (Thickness in × Width in × Length ft ÷ 12) × Pieces

Keep thickness and width in inches and length in feet, then divide by 12. If every measurement is in inches instead, divide by 144. For metric boards, this calculator converts using 1 board foot = 2,359.7 cm³. Multiply the per-piece result by your quantity, then by your price per board foot for total cost.

How many board feet in a 2x6x8? Thickness 2, width 6, length 8: (2 × 6 × 8) ÷ 12 = 8 board feet per board. Buy 10 of them and you have 80 board feet.

Hardwood order: ten 4/4 (1 in thick) walnut boards, 8 in wide, 6 ft long. Per board = (1 × 8 × 6) ÷ 12 = 4 bd ft. Ten boards = 40 bd ft. At $9.50/bd ft that is $380 — open More options and enter the price to confirm.

Decking run: twenty 5/4 deck boards (1.25 in), 6 in wide, 12 ft long → (1.25 × 6 × 12) ÷ 12 = 7.5 bd ft each, 150 bd ft total.

- Use nominal thickness the way the yard does. Hardwood is sold in quarters: 4/4 = 1 in, 5/4 = 1.25 in, 6/4 = 1.5 in, 8/4 = 2 in. Enter that number, not the planed thickness.
- Round up your board length, not down. A board sold as 8 ft may measure 8 ft 2 in; you pay for the nominal length.
- Add 15–20% for waste on projects with cuts, defects, or grain matching — board foot math gives exact volume, not usable yield.
- Softwood dimensional lumber (2x4s, 2x6s) is usually priced per piece, but board feet still help you compare deals across sizes.
- Metric boards? Switch units under More options so centimeters and meters convert correctly.