What Is a Board Foot?

A board foot (BF) is the standard unit of measurement for lumber volume in North America. One board foot equals a piece of wood that is 1 inch thick × 12 inches wide × 12 inches long — or 144 cubic inches.

Quick Reference: This calculator helps you quickly determine how many board feet are in any piece of lumber or log, enabling accurate material estimates and cost calculations for woodworking and construction projects.

Two Calculation Modes

Lumber Mode

For sawn boards and dimensional lumber. Uses the standard formula: Thickness (in) × Width (in) × Length (in) ÷ 144.

Log (Doyle) Mode

For estimating usable board feet from raw logs using the Doyle scale: (Diameter − 4)² × Length ÷ 16.

How to Use

Calculating Board Feet for Lumber

Select Mode

Choose Lumber mode (default setting).

Choose Dimensions

Select a Preset Size from the dropdown, or enter custom dimensions for thickness, width, and length.

Set Units

Each field has its own unit selector — choose inches, feet, centimeters, or millimeters as needed.

Enter Quantity

Set the quantity if you have multiple identical pieces.

View Results

The result updates instantly as you type — no need to click calculate.

Calculating Board Feet for Logs

Switch Mode

Change to Log (Doyle) mode.

Enter Diameter

Input the small-end diameter of the log (must be greater than 4 inches).

Enter Length

Input the log length in your preferred unit.

Get Estimate

The Doyle scale estimate appears automatically.

Building a Material List

Add Items

After calculating board feet for a piece, click Add to List.

Repeat Process

Continue adding each different type of lumber or log in your project.

Review List

The list displays each item's dimensions, quantity, and board feet, along with a running total.

Manage Items

Remove individual items with the × button, or clear everything with Clear All.

Estimating Costs

Expand Section

Open the Cost Estimate section

Enter Price

Input price per board foot and select currency

Adjust Waste

Set waste percentage for cuts and defects

View Total

See subtotal, waste cost, and total cost

Features

Preset Lumber Sizes

Quickly select from 12 common lumber dimensions at standard 8-foot length.

1×4, 1×6 boards
2×4, 2×6, 2×8, 2×10, 2×12 framing
4×4, 6×6 posts
Auto-fill dimensions

Flexible Unit Conversion

Each dimension field has its own unit selector for maximum flexibility.

Inches, feet, centimeters, millimeters
Mix and match units
Automatic internal conversion
Accurate results every time

Doyle Log Scale

Estimate usable lumber yield from raw logs using the widely-used Doyle rule.

Standard in eastern United States
Formula: (D − 4)² × L ÷ 16
Small-end diameter measurement
Most accurate for logs 28"+ diameter

Material List Management

Plan entire projects by tracking multiple lumber items in one organized list.

Add unlimited items
Track dimensions and quantities
Running total calculation
Easy item removal

Cost Estimation with Waste Factor

Get realistic budget estimates with adjustable waste calculations.

Price per board foot input
Adjustable waste factor (default 10%)
Accounts for sawing waste and defects
Subtotal and total cost breakdown

Data Persistence

Your work is automatically saved and restored when you return.

Material list saved locally
Price settings preserved
Waste percentage remembered
Pick up where you left off

Frequently Asked Questions

What is the board foot formula?

For lumber: Thickness (inches) × Width (inches) × Length (inches) ÷ 144.

Example: A 2" × 6" × 8' board = 2 × 6 × 96 ÷ 144 = 8 board feet

How does the Doyle log scale work?

The Doyle formula estimates usable lumber from a log: (Diameter − 4)² × Length ÷ 16, where diameter is measured at the small end in inches and length is in feet.

Important note: The Doyle scale tends to underestimate yield for small logs and is most accurate for logs 28 inches and larger.

What is a typical waste factor?

A waste factor of 10-15% is standard for most woodworking projects. This accounts for saw kerf, defects, knots, and end trimming.

10-15% — Standard projects with quality lumber
15-20% — Complex cuts or lower-grade lumber
20%+ — Intricate designs or highly defective material

How do I calculate cost per board foot?

Multiply the total board feet by the price per board foot. This calculator automates the process — simply enter your price and it displays the subtotal, waste cost, and total.

Cost Calculation Formula

Subtotal = Board Feet × Price per BF
Waste Cost = Subtotal × (Waste % ÷ 100)
Total Cost = Subtotal + Waste Cost

What is the difference between nominal and actual lumber size?

Nominal sizes (like "2×4") refer to the rough-cut dimensions before planing. The actual size after planing and drying is smaller.

Nominal Size

Rough-Cut Dimensions

2×4 (nominal)
2×6 (nominal)
4×4 (nominal)

Actual Size

After Planing

1.5" × 3.5" (actual)
1.5" × 5.5" (actual)
3.5" × 3.5" (actual)

Industry Standard: Board foot calculations in the lumber industry typically use nominal dimensions, not actual measurements.

Is my data saved?

Yes. Your material list, price per BF, and waste percentage are saved locally in your browser and automatically restored when you return.

Material list with all items
Price per board foot setting
Waste percentage preference
Currency selection

Privacy note: All data is stored locally on your device. No information is sent to external servers.