What exactly is a board foot?

It is a volume: 144 cubic inches, equal to a board one inch thick, twelve inches wide and one foot long. Because it measures volume rather than length, boards of very different shapes can contain the same number of board feet.

What is the board foot formula?

Thickness in inches times width in inches times length in inches, divided by 144. If the length is in feet, divide by 12 instead. Multiply by the number of identical pieces for the total.

Why does a 2×4 not measure two inches by four inches?

Because the nominal size refers to the rough-sawn dimension before drying and surfacing. A finished 2×4 measures 1½ by 3½ inches, but lumber is still bought and billed at the nominal size.

What does 4/4 mean for hardwood thickness?

It is thickness in quarters of an inch, so 4/4 is one inch, 5/4 is an inch and a quarter, and 8/4 is two inches. Hardwood is quoted this way because it is often sold rough and thicknessed by the buyer.

Is my cut list stored or uploaded?

No. The rows exist only in the page while it is open, and every calculation happens on your device.

Board Foot Calculator

Add up board feet across a whole cut list, with linear feet, volume and a lumber cost estimate.

The Board Foot Calculator runs entirely in your browser. Your cut list and prices are used only for the totals shown on your device.

Open the Square Footage Calculator

About Board Foot Calculator

Board Foot Calculator prices a stack of lumber the way a yard does. A board foot is 144 cubic inches — a board one inch thick, twelve inches wide and one foot long — and hardwood is sold by that unit regardless of a board's actual shape. Enter thickness, width, length and quantity for each board in your cut list and the total accumulates as you go, alongside linear feet and volume in cubic feet and cubic metres. Two conventions matter and both are handled: dimensions are nominal, so a 2×4 bills as two inches by four even though it measures 1½ by 3½, and stock under an inch thick is normally billed as a full inch.

Features

Multi-row cut list with per-piece and running totals
Length entered in feet or inches per row
Board feet, linear feet and volume in cubic feet and cubic metres
Optional thin-stock rule that bills under-1-inch boards as a full inch
Quarter-thickness reference showing 4/4 through 16/4 in inches
Lumber cost from a price per board foot
Rows can be added and removed as the cut list changes
Everything calculated on your device

How to use the Board Foot Calculator

Enter the thickness, width, length and quantity of the first board
Add a row for each different board size in your cut list
Choose whether thin stock bills as a full inch, as most yards do
Read the total board feet, and add a price per board foot for a cost

Example

Input

10 pieces of 2 in × 4 in × 8 ft

Output

5.333 board feet each · 53.33 board feet total · 80 linear feet

The textbook 2×4×8 works out to 5⅓ board feet, so ten of them are just over 53.

Common errors & troubleshooting

The board feet come out lower than the yard's invoice. — Use nominal dimensions rather than measured ones. A surfaced 2×4 measures 1½ by 3½ inches but bills as 2 by 4, which is roughly 50% more board feet.
Three-quarter inch stock is being billed as a full inch. — That is the default because most yards price it that way. Turn off the thin-stock toggle if your supplier bills the actual thickness.
A row shows no board feet. — Every row needs all four values — thickness, width, length and quantity. A blank or zero in any of them leaves that row out of the total.
Unsure how to enter hardwood quoted in quarters. — Quarters are inches of thickness over four, so 4/4 is one inch, 8/4 is two and 12/4 is three. The reference row on the page lists them all.

Frequently asked questions

What exactly is a board foot?: It is a volume: 144 cubic inches, equal to a board one inch thick, twelve inches wide and one foot long. Because it measures volume rather than length, boards of very different shapes can contain the same number of board feet.
What is the board foot formula?: Thickness in inches times width in inches times length in inches, divided by 144. If the length is in feet, divide by 12 instead. Multiply by the number of identical pieces for the total.
Why does a 2×4 not measure two inches by four inches?: Because the nominal size refers to the rough-sawn dimension before drying and surfacing. A finished 2×4 measures 1½ by 3½ inches, but lumber is still bought and billed at the nominal size.
What does 4/4 mean for hardwood thickness?: It is thickness in quarters of an inch, so 4/4 is one inch, 5/4 is an inch and a quarter, and 8/4 is two inches. Hardwood is quoted this way because it is often sold rough and thicknessed by the buyer.
Is my cut list stored or uploaded?: No. The rows exist only in the page while it is open, and every calculation happens on your device.

Related tools

Square Footage Calculator — Calculate area in square feet or meters for rooms and projects, with cost.
Stair Calculator — Calculate stair rise, run, number of steps and stringer length to code.
Volume Calculator — Calculate the volume of spheres, cylinders, cones, boxes and more.
Concrete Calculator — Estimate concrete volume and bags for slabs, footings and columns.
Brick Calculator — Estimate bricks and mortar for a wall from its size, brick type and joint width.
Drywall Calculator — Estimate drywall sheets, joint compound, tape and screws for a room.