Lumber Calculator

Enter the thickness, width, length and how many boards you have, and get the total board feet, linear feet and cost. Optional price per board foot for a running total.

Use this free lumber calculator to work out the board feet and cost of the boards you're buying. Enter the thickness, width and length of one board, set how many you need, and add a price per board foot for the total. As a board feet calculator it answers how much lumber a project takes and what the yard will charge, since hardwood is sold by the board foot. It also doubles as a wood quantity calculator, giving you total linear feet alongside the volume. Everything runs in your browser.

Lumber

Board size
Quantity

Total board feet

80

10 boards · 80 linear ft

Board feet per board
8
Linear feet
80 ft
Total cost
Figured from
Nominal size

Board feet is a volume measure, not a length. Lumber is usually priced per board foot, so this is the number a yard uses to quote hardwood.

Nominal and actual sizes differ: a "2×4" is really 1.5 × 3.5 inches once dressed. Board feet is conventionally figured from the nominal size, which is the default here. Switch to Actual if you need the true dressed volume.

How it works

  1. 1

    Enter one board

    Type the thickness and width in inches and the length in feet for a single board.

  2. 2

    Set the quantity

    Step the count up or down to match how many identical boards you're buying.

  3. 3

    Read the board feet

    See the total board feet, the linear feet, and the cost if you added a price per board foot.

Instant & 100% private — nothing is uploaded

Every calculation runs locally in your browser. The income, balances and goals you enter stay on your own device and are never sent to a server — nothing is stored, logged or shared.

Frequently asked questions

How do you calculate board feet?
Multiply thickness in inches by width in inches by length in feet, then divide by 12. A 2 in by 6 in by 8 ft board is (2 × 6 × 8) ÷ 12 = 8 board feet. The lumber estimator does this for one board and multiplies by your quantity.
What is a board foot?
A board foot is a volume of lumber equal to a board 1 inch thick, 12 inches wide and 1 foot long, so 144 cubic inches. It measures how much wood you're buying, not its length, which is why hardwood is priced per board foot.
Should I use nominal or actual dimensions?
Board feet is conventionally figured from the nominal size, so a 2×6 is counted as 2 by 6 even though the dressed board is 1.5 by 5.5. Nominal is the default here. Switch to Actual only if you need the true dressed volume.
What's the difference between board feet and linear feet?
Linear feet is just the length of the board. Board feet accounts for thickness and width too, so two boards of the same length hold different board feet if one is wider. This wood quantity calculator shows both.
How accurate is the lumber cost?
The board feet are exact for the sizes you enter, and the cost is exactly board feet times your price per board foot. Yards round and may charge for waste or short-length premiums, so treat the total as a close estimate and confirm the per-board-foot price at the counter.