Start Free Trial

Free tool

Board Foot Calculator

Enter a board’s thickness, width, length, and how many you’re buying — get the total board feet and cost. Free, no signup for the estimate.

Board feet needed

0 bd ft

  • Board feet per board0 bd ft
  • Boards0
  • Total board feet0 bd ft
  • Estimated cost

Turn takeoffs into paid jobs

Get the free Job Pricing Kit — a printable pricing worksheet, the markup & margin cheat-sheet, and clean invoice + quote templates so the job you just measured becomes a professional quote. We’ll email it now.

Free PDF. No spam. Unsubscribe anytime.

How to calculate board feet

Hardwood is sold by the board foot — a unit of volume, not length — so a wider or thicker board costs more at the same length. Get the one formula right and you can price a stack of mixed lumber accurately instead of guessing by the piece.

1. Know the formula

Board feet = thickness (in) × width (in) × length (ft) ÷ 12. That’s because one board foot is 144 cubic inches — a 1 in × 12 in × 1 ft board. The ÷ 12 comes from mixing inches and feet in the same formula.

2. Use the billed thickness

Rough hardwood is figured on nominal thickness in quarters — 4/4 = 1 in, 5/4 = 1.25 in, 8/4 = 2 in — even after surfacing planes a little off. Enter the thickness your supplier is charging for, not the final planed dimension.

3. Multiply by quantity

Figure board feet for one board, then multiply by how many identical boards you’re buying. For a pile of different sizes, run each size and add the totals. The calculator does one size × quantity at a time.

4. Apply the price

Multiply total board feet by the price per board foot for the material cost. If your supplier quotes per piece or per linear foot instead, convert to a per-board-foot number first so the comparison is apples to apples.

Measuring the job is step one. Turning it into a priced, professional quote is faster inside CrewRivet. See the framing calculator, the deck calculator, or the job pricing calculator.

Board foot calculator FAQ

How do I calculate board feet?
A board foot is thickness (in) × width (in) × length (ft), divided by 12. One board foot equals 144 cubic inches of wood — a piece 1 in thick, 12 in wide, and 1 ft long. Enter your board’s dimensions and quantity and the calculator totals the board feet and cost.
What is a board foot?
It’s the standard unit hardwood lumber is sold by — a volume equal to a board 1 in thick, 12 in wide, and 1 ft long (144 cubic inches). Because it’s a volume, a thicker or wider board contains more board feet even at the same length, which is why lumber is priced this way rather than by the linear foot.
Do I use nominal or actual thickness?
For rough hardwood, board feet are figured on the rough (nominal) thickness in quarters — 4/4 is 1 in, 8/4 is 2 in — even after surfacing removes a little. For dimensional softwood, suppliers usually bill the nominal size too. Enter the thickness you’re being charged for.
How do I turn board feet into a price?
Hardwood is quoted per board foot, so multiply the total board feet by the price per board foot. Enter that price and the calculator returns the material cost. Softwood is often quoted per piece or per linear foot instead — check how your supplier bills.
Is the calculator free?
Yes — the live estimate is free with no email required. Enter your email only if you want the free Job Pricing Kit (pricing worksheet, markup cheat-sheet, and invoice + quote templates) sent to your inbox.