Board Foot Calculator
Calculate board feet for lumber and logs instantly. Get cost estimates for 15 wood species, compare log rules, and plan multi-board projects with waste factor. Free for woodworkers and builders.
Board Feet
board feet
Per Board
4 BF
With 10% Waste
4.4 BF
Red Oak (FAS (First and Seconds)) @ $7.50/BF
Conversions
Project Reference
Board Feet Quick Reference
Board feet for common lumber sizes at 8-foot length using nominal dimensions.
How to Use the Board Foot Calculator
Enter Board Dimensions
Select a common lumber size preset (1x6, 2x4, etc.) or enter custom thickness, width, and length. Set the quantity if buying multiple boards. Switch to Log Scale mode for round logs, or Multiple Boards for a full project cut list.
Choose Wood Species and Grade
Select from 15 wood species with current average prices per board foot. Choose the lumber grade (FAS, Select, #1 Common, etc.) which adjusts the price accordingly. Add a waste percentage (10-20% recommended) for realistic project budgets.
Review Results and Cost
See total board feet, cost estimate, and equivalent square feet, cubic feet, and linear feet. For logs, compare Doyle, Scribner, and International rules side by side. The project reference shows typical board feet needed for common woodworking projects.
Why Use Our Board Foot Calculator
3 Calculation Modes
Single board, log scale (Doyle/Scribner/International), and multiple boards with a full cut list for project planning.
15 Wood Species
Pine to teak with current average prices. Includes density and Janka hardness ratings for each species.
Instant Cost Estimates
See total cost based on species, grade, and waste factor. Compare grades from FAS premium to economy #3 Common.
Unit Conversions
Automatically converts board feet to square feet, cubic feet, and linear feet. Useful for flooring and coverage calculations.
Project Reference Guide
Built-in estimates for 8 common projects from cutting boards to kitchen cabinets. Know how much lumber to buy before you start.
Waste Factor Built In
Add 10-25% waste for sawdust, defects, and mistakes. See both raw and waste-adjusted totals and costs.
Complete Guide: Board Feet, Lumber Measurement, and Pricing
What Is a Board Foot and Why Does Lumber Use It?
A board foot (abbreviated BF or BDFT) is a volume measurement equal to a 1-inch thick board that is 12 inches wide and 12 inches long, totaling 144 cubic inches. Hardwood lumber is sold by the board foot because boards come in random widths and lengths. Unlike dimensional lumber (2x4s) sold by the linear foot at fixed prices, hardwood boards vary in size and are priced per board foot.
The board foot system allows fair pricing regardless of board dimensions. A 1-inch x 6-inch x 8-foot board (4 BF) costs the same per board foot as a 1-inch x 10-inch x 12-foot board (10 BF) of the same species and grade. This standardization has been used in the North American lumber industry since the 19th century.
The Board Foot Formula Explained
The formula is straightforward: Board Feet = (Thickness x Width x Length) / 12, where thickness and width are in inches and length is in feet. Alternatively, if all measurements are in inches: Board Feet = (T x W x L) / 144. A 1-inch thick, 8-inch wide, 10-foot long board contains (1 x 8 x 10) / 12 = 6.67 board feet.
For lumber thicker than 1 inch, the quarter system is used: 4/4 (four-quarter) means 1 inch thick, 5/4 means 1.25 inches, 6/4 means 1.5 inches, 8/4 means 2 inches, and 12/4 means 3 inches. These are rough-sawn thicknesses before planing. After surfacing (S2S), a 4/4 board becomes approximately 13/16 inch thick, and an 8/4 board becomes approximately 1-3/4 inches.
Log Scaling: Doyle, Scribner, and International Rules
Log rules estimate how many board feet of lumber can be sawn from a log. The three main rules are the Doyle rule, the Scribner rule, and the International 1/4-inch rule. Each uses a different formula and produces different estimates, especially for smaller logs.
The Doyle rule, the simplest formula, significantly underestimates yield for small logs under 20 inches diameter, which benefits the buyer. The Scribner rule is more accurate for small logs and is commonly used by the US Forest Service. The International 1/4-inch rule is considered the most accurate overall and is used as the standard by the USDA Forest Products Laboratory. For a 16-inch diameter, 16-foot log, Doyle gives 144 BF, Scribner gives about 150 BF, and International gives about 185 BF.
Hardwood Lumber Grades: FAS to #3 Common
The National Hardwood Lumber Association (NHLA) grades hardwood lumber based on the percentage of clear, defect-free wood. FAS (First and Seconds) is the highest grade, requiring 83% or more clear on the worst face, with minimum board size of 6 inches wide and 8 feet long. It commands the highest prices and is used for fine furniture and architectural millwork.
Select grade requires 83% clear on the best face only. #1 Common requires 66% clear and is the most popular grade for furniture making because it offers a good balance of quality and price. #2 Common (50% clear) works well for smaller projects and cabinet parts. #3 Common (33% clear) is economy grade suitable for pallets, crating, and rustic applications where character marks are acceptable or desired.
How to Estimate Lumber for a Project
Start by creating a cut list: every piece needed with exact dimensions. Add the board feet for all pieces, then apply a waste factor. For straight cuts with good lumber, 10% waste is adequate. For projects with many angled cuts, complex joinery, or lower-grade lumber, use 15-20%. If you are working with rough-sawn lumber that needs surfacing, add an extra 1/4 inch to both thickness and width before calculating board feet.
When shopping, remember that longer and wider boards cost the same per board foot but are more efficient because you get fewer cutoffs. A single 1x10x10 gives you 8.33 BF with one board. Three 1x4x8 boards give you 8 BF with three boards and potentially more waste from multiple cuts. For premium species like walnut, efficiency in cutting can save significant money.
Board Foot Calculator FAQ
Common questions about board feet, lumber measurement, and pricing.
Disclaimer: This Board Foot Calculator provides estimates based on standard lumber measurement formulas. Actual lumber prices vary by region, supplier, and market conditions. Wood species prices shown are approximate national averages. Log scale estimates may differ from actual mill yield. Always get quotes from your local lumber yard for accurate pricing.