Board Feet Calculator — Calculate Lumber Board Footage
Calculate board feet from timber dimensions. Enter thickness, width, and length to get board footage for lumber purchasing.
Nominal (rough-sawn) thickness
Leave blank to skip cost estimate
How We Calculate This
This calculator uses the standard board feet formula used by timber merchants and sawmills worldwide.
The formula
Board Feet = (Thickness × Width × Length) ÷ 144
Where thickness and width are in inches, and length is in inches. When length is in feet, the formula becomes:
Board Feet = (Thickness in inches × Width in inches × Length in feet) ÷ 12
Metric conversion
If you enter measurements in millimetres, the calculator first converts to inches (÷ 25.4 for thickness and width, ÷ 304.8 for length in feet) before applying the formula.
Cost estimate
If you enter a price per board foot, the calculator multiplies the total board footage by your unit price to give an estimated material cost.
Frequently Asked Questions
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Last updated: February 2026
All calculations are estimates. Always verify measurements and material quantities before cutting or purchasing.