Board Feet Calculator
Professional lumber measurement tool for woodworkers, contractors & timber buyers
Board Feet Calculator
Calculation Results
Formula Used
Board Feet = (Thickness × Width × Length) ÷ 12 = (T in × W in × L ft) ÷ 12
Lumber Cost Estimator
Cost Estimate
Doyle Log Scale Calculator
Log Scale Results
Doyle Rule Formula
Board Feet = ((D - 4)² × L) ÷ 16 where D = diameter (in), L = length (ft)
Lumber Unit Converter
Conversion Result
Quick Reference
| From | To | Formula |
|---|---|---|
| Board Feet | Linear Feet | LF = BF × 12 ÷ (Width × Thickness) |
| Board Feet | Cubic Feet | Cu Ft = BF ÷ 12 |
| Board Feet | Square Feet | Sq Ft = BF ÷ Thickness |
What Is a Board Foot?
A board foot (BF or BDFT) is the standard measure for lumber volume in the United States and Canada. One board foot consists of a piece of wood that is 12 inches long × 12 inches wide × 1 inch thick. A given piece of wood is 144 cubic inches when it is in such form.
Generally speaking, board feet are not considered area measurements like square feet and linear feet, which measure length. This is good for calculating prices comparing pieces of lumber to each other or other estimates, considering that most hardwoods come with varied widths and thinnesses and when volume must be taken into account as compared to area.
Key Uses of Board Feet
Fair Pricing
Promotes fair prices regardless of the lumber size.
Project Planning
Used in efficient structuring of wool materials for furniture.
Industry Standard
Used by lumber shops, sawmills, and woodworkers nationwide.
Cost Control
Helps avoid overbuying and reduces material waste.
How to Find Board Feet
Calculating board feet is straightforward if you understand the mathematical formula. Remember: You will need three numbers or dimensions for calculation: the thickness, the width, and the length.
Step by Step Calculation
Estimate the Thickness
The thickness is in inches. For approximate lumber, use some finished thickness. The standard rough lumber thicknesses are 4/4 (1 inch), 5/4 (1.25 inches), 6/4 (1.5 inches), and 8/4 (2 inches).
Estimate the Width
Width measurement is in inches. If the width changes frequently along the piece, measure at the narrowest point or divide the width into sections and take an average.
Estimate the Length
The length will be measured in feet. Round accurately to the approximate feet.
Now, Apply the Formula
For calculating board feet, you must multiply the thickness, width, and length in inches, and then divide by 12.
Formulas
An Illustration
Quick Reference Tables
Board Feet For Common Lumber Sizes
| Lumber Size | 6ft Length | 8ft Length | 10ft Length | 12ft Length |
|---|---|---|---|---|
| 1" × 4" | 2.00 BF | 2.67 BF | 3.33 BF | 4.00 BF |
| 1" × 6" | 3.00 BF | 4.00 BF | 5.00 BF | 6.00 BF |
| 1" × 8" | 4.00 BF | 5.33 BF | 6.67 BF | 8.00 BF |
| 1" × 10" | 5.00 BF | 6.67 BF | 8.33 BF | 10.00 BF |
| 1" × 12" | 6.00 BF | 8.00 BF | 10.00 BF | 12.00 BF |
| 2" × 4" | 4.00 BF | 5.33 BF | 6.67 BF | 8.00 BF |
| 2" × 6" | 6.00 BF | 8.00 BF | 10.00 BF | 12.00 BF |
| 2" × 8" | 8.00 BF | 10.67 BF | 13.33 BF | 16.00 BF |
Hardwood Thickness Guide
| Quarter Notation | Rough Thickness | Surfaced (S2S) | Use |
|---|---|---|---|
| 4/4 | 1" | 13/16" (0.8125") | Paneling, Small Parts, Trim |
| 5/4 | 1.25" | 1-1/16" (1.0625") | Doing Powellsa Und Furniture Rails |
| 6/4 | 1.5" | 1-5/16" (1.3125") | Kitchenep, Cabinet Doors |
| 8/4 | 2" | 1-13/16" (1.8125") | Kitchenep, Benotheys |
| 10/4 | 2.5" | 2-5/16" (2.3125") | Workbenches, Turning |
| 12/4 | 3" | 2-13/16" (2.8125") | Heavy Furniture, Mantels |
| 16/4 | 4" | 3-13/16" (3.8125") | Tipping, Very Large Turnings |
Board Feet and Other Measures
A sound grasp of the distinction between board feet and other lumber measurements is vital for precise estimating and buying.
Board Feet
This measures volume, taking into account thicknesses, widths, and lengths. Such is used for pricing hardwood.
Linear Foot
This measures length alone, disregarding width and thickness, the measurement being synonymous with the terms dimensional lumber or molding.
Square Foot
Measuring an area, width and length being the only two factors accounted for. This measurement is used in the estimate of gains made from having installed flooring and plywood.
Frequently Asked Questions (FAQs)
The board feet calculator uses a formula for board foot: (Width in inches x Thickness in inches x Length in feet)/12, in order to work out board footage. Simply because one board foot occupies 144 cubic inches (1 inch thick by 12 inches wide x 12-inch length), when the measurements are multiplied, the calculator divides by 12 to convert cubic inches into board-feet (bdft).
To measure volume, the board foot is used (one board foot = 144 cubic inches); area is measured in square feet. A board foot is used for lumber estimation to include thickness as well as what width and length contribute; square footage ignores thickness. Converting from board feet to square feet, you must further include the thickness in inches.
Use the lumber calculator approach: for each board, multiply width (inches) × thickness (inches) × length (feet) ÷ 12 to get board feet per board, then multiply by the number of boards, or sum the answers. For nominal sizes (e.g., 1 inch thick), remember actual thickness may differ.
Board-foot rules for hardwood are the same: (Width in inches × Thickness in inches × Length in feet) ÷12. The price per board foot can be approximated based on the total board footage times the price model. When dealing with hardwood lumber, one should specify the actual dimensions.
Estimation of board-footage from standing trees requires products to be reviewed in terms of log-scale methods and measurement dominate at diameter to the breast-height. Consulting log-scale tables of several rules (Doyle, Scribner) is a useful means to estimate board feet.
Divide the piece into sections of uniform width and thickness for board feet estimation in case of planks or tapers. Measure the board footage applicable to each of the sections in turn, totaling the measurements. For an easier option, generalize/calculate the average figure.
To get the maximum benefit from a lumber calculator, you should enter exact measurements in the form (true thickness, inches wide, length in feet) for each piece. Select the correct unit, board feet, for metering, and also input the price per board foot if you want costing.