# How to Calculate Board Feet

Hardwood lumber is typically sold per board foot when purchased in bulk. The board footage is calculated before the lumber is surfaced, planed or sanded.

## Based on Volume

Board foot is a calculation of volume, allowing for numerous boards to be tallied up at the same time, even though they are various widths.

## In the Rough

Calculations of board foot are typically based on rough, nondimensioned lumber. Rough lumber is exactly what the name implies; it appears fuzzy, with loose fibers, and is typically not consistent in width or thickness.

## Thickness and Length

Typical thicknesses for rough lumber are 1 or 2 inches, also commonly referred to as 4/4, or four-quarter, and 8/4, or eight-quarter. Length is somewhat consistent for dimensioned or rough lumber, even though each piece may be a few inches longer or shorter than the stated size. The length is rounded to the nearest foot.

## Dimensioned Lumber

You can purchase dimensioned lumber -- lumber that has been surfaced or sanded -- using board-foot calculations, by rounding the thickness up to the nearest inch. It's a common practice and widely accepted by woodworkers. Prices for dimensioned lumber calculated in board footage typically reflect the price of sanding, planing or milling.

## By Definition

A single board foot of lumber measures 1 inch thick, 12 inches wide and 12 inches long. The formula for calculating board feet is first to multiply thickness by width by length -- in inches. Then divide the total by 144 for the total board footage of a given board.

## Calculation Example

Suppose you have a board that measures 1 inch by 12 inches by 96 inches. Multiply the three dimensions together to get 1,152. Divide 1,152 by 144 to get the actual board feet, which is 8.

## Step 1 Measure the Width

Measure the width of individual boards, and write each measurement down on a piece of paper. Add the numbers together.

## Step 2 Measure the Length

Measure the length of one board only. There might be slight differences in the length of individual boards; that's fine. Round it to the nearest 12-inch mark. For example, write 96 inches for an 8-foot board.

## Step 3 Use the Formula

Multiply the numbers for total width, length and thickness. Divide that number by 144 to get the board footage of all the boards combined.

## Calculate by Layer

Woodworkers may calculate board feet by layer. For example, the back of a pickup truck is about 48 inches wide. Using the formula, a single layer of hardwood -- 96 inches in length -- in the back of the truck equals approximately 32 board feet. If you stack four layers on the truck -- 4 x 32 -- the total board footage is 128.

## Calculate Eight-Quarter

It's not often that you purchase rough lumber thicker than 1 inch, and rough lumber doesn't typically graduate in fractions. Occasionally, however, if you want to purchase 8/4 rough lumber, which is 2 inches thick, calculate for a 1-inch thickness and then double the board footage.

## MBF Pricing

Sometimes lumber is priced per MBF, or 1,000 board feet. If you want to buy 250 board feet of lumber, for example, and it costs \$500 per MBF, divide 250 by 1,000 to get 0.25 MBF, then multiply that by \$500 to get a price of \$125.