Board Foot Calculator
This free board foot calculator helps you estimate lumber volume and total project costs in seconds. Whether you are running a board foot calculator for rough sawn lumber at the local sawmill or planning framing packs for a build, compute your exact tally below to prevent expensive material shortfalls.
What is a Board Foot?
A board foot (BF or FBM) is a standard North American measurement of lumber volume. One board foot equals an uncut volume of 144 cubic inches—equivalent to a piece of wood 12 inches wide, 12 inches long, and 1 inch thick.
Commercial timber yards and sawmills use board feet to price raw stock uniformly. Understanding how to calculate board feet in lumber makes it simple to price rough cuts, track wood inventory across varying board widths, and compare kiln-dried vs. green lumber costs.
What is the Formula for Board Feet?
Learn how to calculate board feet in lumber using the standard equation: Thickness (in) × Width (in) × Length (ft) ÷ 12. When your length is recorded in inches, use Thickness x Width x Length ÷ 144.
Board Feet (BF) = [Thickness (in) × Width (in) × Length (ft)] / 12Board Feet (BF) = [Thickness (in) × Width (in) × Length (in)] / 144Nominal vs. Actual Lumber Dimensions
Always base your lumber volume calculations on nominal vs. actual lumber dimensions. Nominal sizing refers to the rough green board before it is dried, planed, and surfaced (S4S):
- 4/4 Hardwood (FAS/Select): 1" nominal rough thickness, surfaced to 3/4" or 13/16" actual.
- 6/4 Hardwood: 1.5" nominal rough thickness, surfaced down to 1-1/4" actual.
- 8/4 Hardwood: 2.0" nominal rough thickness, surfaced down to 1-3/4" actual.
- 2x4 Softwood Stud: 2" × 4" nominal size, measuring 1-1/2" × 3-1/2" actual.
Sawmills bill timber according to rough nominal lumber tallies. If you calculate volume using surfaced, actual dimensions, you will understate how much raw wood you need to purchase.
Lumber Pricing & Project Estimating
Lumber cost per board foot calculator
Understanding hardwood vs. softwood pricing is essential for budgeting. Softwoods are commonly priced by the linear stick, whereas fine hardwoods (such as Walnut, Hard Maple, and White Oak) sell by the board foot or by the thousand board feet (MBF / $/MBF). Total material cost is calculated as:
Total Cost = Board Feet × Cost per Board Foot. For example, 80 BF of FAS Cherry at $7.25/BF yields a $580.00 material total.
Board feet to linear feet conversion calculator
When comparing linear feet vs. board feet, remember linear footage tracks only length. Use this conversion: Linear Feet = (Board Feet × 12) ÷ (Thickness in inches × Width in inches).
How many board feet do I need for a project?
To determine how many board feet do I need for a project, calculate the total volume across your cut list and add a standard waste factor / overage percentage (15% to 20% for Common lumber grades, or 10% for FAS boards) to account for jointing, knots, and end checking.
Frequently Asked Questions
How do you calculate board feet?
To calculate board feet, multiply the board's nominal thickness (inches) by nominal width (inches) and length (feet), then divide by 12. If length is in inches, multiply thickness × width × length and divide by 144.
What is the formula for board feet?
The standard board foot formula is: Board Feet = (Thickness in inches × Width in inches × Length in feet) ÷ 12. When all measurements are in inches, use: (Thickness × Width × Length) ÷ 144.
How many board feet are in a 2x4x8?
A standard nominal 2x4 stud measuring 8 feet long contains exactly 5.33 board feet. Here is the worked step-by-step math:
Is board foot the same as square foot?
No. A square foot measures two-dimensional surface area (144 square inches with no thickness considered). A board foot measures three-dimensional timber volume equal to 144 cubic inches (12 inches wide × 12 inches long × 1 inch thick).
How much does lumber cost per board foot?
Lumber costs vary widely by species and grade. Construction softwoods typically cost between $1.00 and $3.00 per board foot, domestic hardwoods (like Oak or Maple) range from $4.00 to $12.00 per board foot, and select exotics can exceed $20.00 to $40.00 per board foot.
Board Foot Calculator
Total Board Footage Required
Includes 0 LF linear length and 0.0000 m³ total volume metrics.
Estimated Total Cost
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