Board Feet Calculator for Lumber
Work out how much lumber a project needs in board feet. Enter a board's thickness and width in inches, its length in feet, the quantity, and an optional price.
How to calculate board feet
- Enter the board thickness and width in inches and the length in feet.
- Set how many identical boards you are buying.
- Add a price per board foot to see the total cost, then copy your estimate.
Examples
Ten 1x6 boards, 8 ft long
Thickness 1 in, width 6 in, length 8 ft, quantity 10
4 board feet each, 40 board feet total
Frequently asked questions
What is a board foot?
A board foot is a unit of lumber volume equal to a piece 1 inch thick, 12 inches wide and 1 foot long, or 144 cubic inches. Hardwood is usually priced by the board foot.
How do you calculate board feet?
Multiply the board thickness in inches by the width in inches by the length in feet, then divide by 12. Multiply that by the number of boards for the project total.
Should I use nominal or actual lumber sizes?
Board feet are figured from nominal sizes, so a 2x4 counts as 2 by 4 even though the dressed board is smaller. Use the nominal numbers stamped on the lumber.
Why is my 2x4 not a whole number of board feet?
A 2x4 at 8 feet is 2 times 4 times 8 divided by 12, which is 5.33 board feet. Many common sizes give fractions, which is normal and not a rounding error.
Does this include waste?
No. The result is the exact volume of the boards you enter. Add a few extra boards yourself to cover offcuts, defects and mistakes on the job.
Related tools
Deck Calculator
Estimate deck boards, joists and screws for a deck. Enter length and width, set board size, gap and joist spacing, and add waste for cuts.
Fence Calculator
Estimate posts, sections, rails and pickets for a fence. Enter total length and post spacing, set rails per section and picket width, and add gates.
Concrete Calculator
Calculate concrete for a slab or footing. Enter length, width and thickness to get cubic yards plus 60 and 80 lb bag counts, with a waste allowance.
Appliance Energy Calculator
Find what an appliance costs to run from its wattage. Enter watts, hours per day and your rate to see kWh and cost per day, month and year.
Aquarium Volume Calculator
Calculate your fish tank volume in gallons and liters from inside dimensions in inches. Set a fill level to estimate the actual water it holds.
Baseboard Calculator
Estimate linear feet and pieces of baseboard or trim for a room. Enter length and width, subtract doorways, set piece length and add waste.