Board Foot Calculator

A board foot is a unit of lumber volume. One board foot represents a piece of wood measuring 1 foot long, 1 foot wide, and 1 inch thick.

Because board feet measure volume, the calculation accounts for the length, width, and thickness of the lumber rather than length alone.

One board foot is equal to 144 cubic inches.

For example, a board measuring 1 foot long, 12 inches wide, and 1 inch thick contains 1 board foot.

For lumber dimensions measured in inches for thickness and width and feet for length, multiply the thickness, width, and length, then divide by 12.

For example, a board that is 2 inches thick, 6 inches wide, and 10 feet long contains 10 board feet.

The calculator performs the applicable unit conversions based on its supported inputs.

The standard board-foot formula uses thickness and width in inches and length in feet.

The formula works because a board foot represents 144 cubic inches, while a length measured in feet contributes 12 inches to the calculation.

If all three dimensions are first converted to inches, the equivalent formula divides the resulting cubic-inch volume by 144.

Both approaches produce the same board-foot measurement when the dimensions are converted consistently.

Board feet are commonly used when discussing lumber volume. A board-foot measurement allows different pieces of lumber to be compared based on their total volume rather than simply their length or surface area.

For example, a thick, narrow board and a thin, wide board can have different dimensions but similar total board footage.

This makes board feet useful when estimating and comparing the volume of rough lumber.

The board-foot calculation describes volume; it does not automatically determine the number of physical boards required for a particular construction project.

The total board footage depends on the dimensions and quantity of the lumber being considered.

For one board, calculate the board footage using thickness × width × length ÷ 12.

If several boards have identical dimensions, you can calculate the board footage of one board and multiply it by the number of boards.

If boards have different dimensions, calculate each group separately and add the results.

The current calculator should only be described as calculating multiple-board quantities if the interface actually includes a quantity input.

Board feet and linear feet measure different things.

Linear feet measure length only, while board feet measure lumber volume by incorporating length, width, and thickness.

For example, two boards can both be 10 linear feet long while having very different board-foot measurements if their widths or thicknesses differ.

A linear-foot measurement alone cannot determine board feet without knowing the board's width and thickness.

Both board feet and cubic feet describe volume, but they use different conventions.

A board foot represents 144 cubic inches, while a cubic foot represents 1,728 cubic inches.

Therefore, one cubic foot contains 12 board feet, and one board foot equals one-twelfth of a cubic foot.

Board feet are especially useful for lumber because the unit is based on the traditional dimensions used to describe boards.

For general three-dimensional volume calculations, use the Cubic Feet Calculator.

Lumber is often described using nominal dimensions, but the actual dimensions of a piece can differ from its nominal size.

For a board-foot calculation, use the dimensions that correspond to the lumber measurement you are trying to calculate.

Do not automatically assume that a board described commercially by a particular nominal size has exactly those physical dimensions.

When estimating lumber volume, clearly distinguish between nominal lumber descriptions and actual measured dimensions.

The board-foot calculation is useful for many lumber-related measurements.

Common applications include estimating rough lumber volume, comparing lumber quantities, calculating board footage for groups of boards manually, estimating lumber volume before purchasing, and comparing different board dimensions.

The calculator determines board footage from the dimensions entered.

It does not automatically determine whether a particular lumber size is appropriate for a structural application.

If several boards have identical dimensions, the total board footage can be calculated by multiplying the board-foot measurement of one board by the number of boards.

For example, if one board contains 8 board feet and there are 10 identical boards, the total is 80 board feet.

If the boards have different dimensions, calculate each group separately and add the results.

Only describe a quantity-based calculation as part of the calculator itself if the current implementation provides a quantity input.

Because board-foot calculations are based on lumber dimensions, measurements are often given in inches.

When thickness and width are measured in inches and length is measured in feet, use the standard board-foot formula.

If all three dimensions are measured in inches, multiply the three dimensions and divide by 144.

For example, a board measuring 2 inches thick, 8 inches wide, and 72 inches long contains 8 board feet.

The important part is keeping the units consistent with the formula being used.

The following examples demonstrate how the standard board-foot formula works with common lumber dimensions.

A 1 × 6 × 10 board contains 5 board feet.

A 2 × 8 × 12 board contains 16 board feet.

A 2 × 6 × 8 board contains 8 board feet.

These examples demonstrate the calculation and should not be presented as purchasing recommendations.

You can verify a board-foot calculation with the standard formula.

For example, consider a board that is 2 inches thick, 6 inches wide, and 10 feet long.

Multiply the dimensions: 2 × 6 × 10 = 120.

Then divide by 12: 120 ÷ 12 = 10 board feet.

If the calculator produces a different result, check the dimensions and units entered.

Board feet are sometimes used as a basis for describing lumber prices.

A price expressed per board foot is different from a price expressed per physical board or per linear foot.

The general relationship for a price-per-board-foot calculation is board feet multiplied by the price per board foot.

However, do not imply that the CalConstruct calculator provides lumber pricing unless the current implementation actually includes a price input and cost result.

For actual purchasing, lumber prices can vary by species, grade, dimensions, supplier, location, and market conditions.

Board-foot measurements can also be discussed in relation to logs, but logs are not rectangular boards.

A log requires a different geometric approach and may use log-scaling conventions rather than the simple rectangular board-foot formula.

Do not describe the current calculator as a log board foot calculator unless the implementation explicitly supports logs.

For a standard rectangular board, use the standard board-foot formula.

Before calculating board footage, measure the board thickness, width, and length and record the units used.

Enter the dimensions into the calculator and select the appropriate supported units.

For rough or irregular lumber, measurements should represent the dimensions relevant to the volume being calculated.

Use the actual dimensions required by the calculation rather than automatically substituting nominal lumber dimensions.

For general volume calculations expressed in cubic feet, use the Cubic Feet Calculator.

For larger material volumes measured in cubic yards, use the Cubic Yard Calculator.

If you need to calculate an area before working with lumber dimensions, use the Square Footage Calculator.

For stair-dimension calculations, use the Stair Calculator.