Board Foot Calculator

This board foot calculator helps you determine lumber volume. Input thickness, width, length, and quantity to get board feet and total board feet.

Enter Dimensions

Quick Presets:

Board Feet Results

Total Volume

0 board feet

Calculation Process:

Step 1: Convert to inches Enter dimensions
Step 2: Apply formula T × W × L ÷ 144
Step 3: Multiply by pieces × 1 piece(s)
Final calculation: 0 BF

Cost Estimate

$

Total Project Cost

$0.00

Board Foot Calculator Guide

Professional insights from lumber industry experts

What is a Board Foot?

Important: Forget length (that's linear feet—tracked by linear foot calculators). Forget area (that's square feet). A board foot measures volume—the actual "meat" of the lumber.

The Golden Rule:

1 board foot = 144 cubic inches of wood

Picture a slab that's 1 inch thick × 12 inches wide × 12 inches long

🤔 Why's It Confusing?

Newbies walk in thinking a "foot" means length. Nope! A board 1 foot long can hold multiple board feet if it's thick or wide enough.

Example:

A chunk of 2" thick × 6" wide × 1' long? → (2 × 6 × 1) / 12 = 1 board foot

Same length but 3" thick × 8" wide? → (3 × 8 × 1) / 12 = 2 board feet

See? Length alone doesn't tell the story.

How to Calculate Board Feet

Here's the dirt-simple formula every woodworker should know:

Board Feet Formula

Board Feet = (Thickness × Width × Length) / 12

Units: Thickness & Width in INCHES, Length in FEET

Common Lumber Calculations:

1x4x8 board: (1 × 4 × 8) / 12 = 2.67 BF
2x6x16 lumber: (2 × 6 × 16) / 12 = 16 BF
10 foot 2x4: (2 × 4 × 10) / 12 = 6.67 BF
1.25 x 4 x 8: (1.25 × 4 × 8) / 12 = 3.33 BF

Pro Tips:

  • • For logs or slabs, use a log board foot calculator or Doyle Scale
  • • 6'×4' butcher block at 1.5" thick? Convert feet to inches: (1.5 × 48 × 72) / 144 = 36 BF
  • • Always bookmark a BF calculator app for quick calculations

⚠️ Don't Step on These Rakes!

Nominal vs. Actual Size

A "2×4" isn't really 2"×4". After drying/planing, it's closer to 1.5"×3.5". Always use nominal dimensions for BF calculations—not the skinny finished size.

Mixed Units Problem

Measured length in inches (e.g., a scrap)? Divide by 144, not 12. The formula changes when all measurements are in inches.

Rough Lumber Measuring

Measure actual width at the narrowest point—no rounding up! That "8-inch wide" slab might taper to 7.5".

🔁 Converting Board Feet to Other Units

→ Square Feet

Divide BF by thickness (in inches)

Example: 150 BF of 3"-thick wood = 150 ÷ 3 = 50 sq ft

→ Linear Feet

Not directly convertible!

Linear feet ignore thickness/width. Use a linear feet calculator for that.

Board feet calculator Q&A

How do I figure BF in a log?

Measure diameter + length, plug into a log board feet calculator (Doyle Scale's gold standard). Alternative formula: ((Diameter - 4)/4)² × Length.

What's the difference between board foot and linear foot?

BF = volume (thickness × width × length). Linear foot = just length. You pay for volume in lumber, not just length!

How many board feet are in a 2x4?

Depends on length:

6 ft: 4 BF
8 ft: 5⅓ BF
10 ft: 6⅔ BF
12 ft: 8 BF
16 ft: 10⅔ BF
20 ft: 13⅓ BF

Any final tips for lumber buying?

🔨 Pro Tip: Lumber prices swing with supply. Always ask your yard which species are priced sharp—and check for a contractor's edge on rough boards to save jointing time.

Bottom line: Board feet keep lumber deals honest. You pay for volume, not just length!