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Board Foot Calculator

Calculate board feet for lumber purchases — with common size presets, nominal vs actual dimensions, project list, and price estimation

Board Feet

8.00 BF

(2" × 6" × 8') ÷ 12 = 8.00

$

About This Tool

A board foot is the standard unit for measuring and pricing lumber in North America. One board foot equals a piece of wood 1 inch thick, 12 inches wide, and 1 foot long — or 144 cubic inches. Whether you're buying hardwood from a mill, framing a deck, or pricing a woodworking project, you need to know how many board feet you're dealing with. This calculator handles the math instantly for any lumber dimensions. Pick from common presets like 2x4, 2x6, or 2x12, or enter custom dimensions. It shows both nominal and actual board feet side by side, so you always know exactly what you're getting. Add multiple lumber items to a project list and get a total with optional price estimation. The formula is straightforward — thickness times width times length divided by 12 — but when you're pricing 6 different lumber sizes for a project, doing it by hand gets tedious. This tool does it in seconds and gives you a shareable link to save your lumber list.

How to Use

1. Click a preset button (like 2x4 or 2x6) to fill in common lumber dimensions, or enter custom thickness and width 2. Enter the board length in feet (standard lumber lengths: 8, 10, 12, 14, 16 ft) 3. Enter the number of pieces you need 4. Read the instant result showing board feet for the current inputs 5. Click "+ Add to Project List" to save the item and start building a multi-item lumber list 6. Optionally enter a price per board foot to see cost estimates 7. Use "Copy List" to copy a formatted summary or "Copy Link" to share your lumber list

Formula

Board Feet = (Thickness in inches x Width in inches x Length in feet) / 12 Example with nominal dimensions: A 2x6x8 board: (2 x 6 x 8) / 12 = 8.00 board feet Example with actual dimensions: A 2x6 is actually 1.5" x 5.5": (1.5 x 5.5 x 8) / 12 = 5.50 board feet For multiple pieces: Total BF = Board Feet per piece x Quantity MBF (thousand board feet) = Total BF / 1000

Frequently Asked Questions

What is a board foot?
A board foot (BF) is a unit of volume for lumber equal to 144 cubic inches — a piece 1 inch thick, 12 inches wide, and 1 foot long. It's the standard measure used to buy and sell hardwood and specialty lumber in North America. Softwood framing lumber (like 2x4s) is usually sold by the linear foot, but board feet are still used for pricing and estimating.
How many board feet in a 2x4x8?
Using nominal dimensions (2" x 4" x 8'), a 2x4x8 contains (2 x 4 x 8) / 12 = 5.33 board feet. Using actual dimensions (1.5" x 3.5" x 8'), it contains (1.5 x 3.5 x 8) / 12 = 3.50 board feet. Lumber yards typically price using nominal dimensions, but actual board feet reflect the real wood volume.
What is the difference between nominal and actual lumber dimensions?
Nominal dimensions are the 'name' of the lumber (2x4, 2x6, etc.) — the rough size before drying and planing. Actual dimensions are smaller: a 2x4 is actually 1.5" x 3.5", a 2x6 is 1.5" x 5.5", and a 1x8 is 0.75" x 7.25". The difference matters when calculating real wood volume. Hardwood is typically sold by actual measured thickness in quarter-inch increments (4/4, 5/4, 6/4, 8/4).
How much does lumber cost per board foot?
Lumber prices vary widely by species, grade, and market conditions. Common softwoods like pine or spruce run $2-6 per board foot. Hardwoods range from $3-8 for poplar or soft maple to $8-15+ for cherry, walnut, or white oak. Exotic species can exceed $20/BF. Prices also vary by thickness — thicker stock costs more per board foot. Check local suppliers for current pricing.
What does MBF mean in lumber?
MBF stands for 'thousand board feet' (M is the Roman numeral for 1,000). It's used for pricing bulk lumber. If lumber is quoted at $800/MBF, that's $0.80 per board foot. MBF is common in sawmill pricing, timber sales, and wholesale lumber markets. For smaller purchases, price per board foot ($/BF) is more practical.
How do I calculate board feet for rough-sawn hardwood?
For rough-sawn hardwood, use the actual measured thickness and width — there are no nominal adjustments. Hardwood thickness is expressed in quarters: 4/4 (1 inch), 5/4 (1.25 inches), 6/4 (1.5 inches), 8/4 (2 inches). Measure the width at the narrowest point. The formula is the same: (thickness x width x length) / 12. Most hardwood dealers measure each board individually since widths vary.
How many board feet do I need for a project?
Add up the board feet for each component of your project, then add 15-20% for waste (cutting, defects, mistakes). For example, a simple bookshelf with 5 shelves at 1x10x36" and 2 sides at 1x10x48" would need about 25 board feet of material. Add 20% waste and you should buy about 30 board feet. Use the project list feature in this calculator to total up multiple lumber sizes.

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