Free Lumber Estimation Suite

Board Foot Calculator

Calculate lumber volume and cost instantly. Enter your board dimensions below and our tool applies the industry-standard board foot formula in real time — trusted by woodworkers, sawmills, contractors, and hardwood dealers worldwide.

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Free Online Board Foot Calculator

Enter dimensions — results update instantly.

Thickness
Width
Length
ft
in
Cost Estimator

What Is a Board Foot?

A board foot is the standard unit of volume used in the North American lumber industry. It measures three dimensions — length, width, and thickness — making it ideal for pricing hardwood species like oak, walnut, maple, and cherry.

Interactive Board Dimension Diagram

Enter values in the calculator above — this diagram updates in real time.

Length: 0 ft Width: 0 in Thickness: 0 in Board Feet 0.00 BF
📐
1 Board Foot = 144 cubic inches

Base volumetric unit for the lumber trade

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1 Board Foot = 12 in × 12 in × 1 in

One foot long, one foot wide, one inch thick

📊
Volume, not area

Board feet account for thickness — unlike square feet

Why Lumber Is Measured in Board Feet

Hardwood — oak, walnut, maple, cherry — is almost always priced per board foot. This gives sawmills and lumber yards one consistent pricing unit regardless of board size. Whether you buy a single plank or a full pallet, the math scales.

Board Foot Formula

Interactive Formula Visualizer

Values fill in live from the calculator above.

Length0ft
×
Width0in
×
Thickness0in
÷
12
=
Result0.00BF

Step-by-Step Guide

1

Measure Length

Measure the board's length in feet. Divide inches by 12 if needed.

2

Measure Width

Measure width in inches at the widest usable point.

3

Measure Thickness

Use actual thickness — a surfaced "1-inch" board is really ¾ in.

4

Apply Formula

Length × Width × Thickness ÷ 12 — multiply by quantity.

Calculation Example

Building a dining table with 5 boards of white oak: 8 ft long, 10 in wide, 1.25 in thick (5/4 rough-sawn).

StepCalculation
Formula8 × 10 × 1.25 ÷ 12
Per Piece8.33 BF
Total (×5)41.67 BF
ItemValue
Total Board Feet41.67 BF
Price per BF$4.15
Total Cost$172.93

💡 Add 10–15 % extra for waste from cuts, defects, and grain matching.

Common Lumber Sizes & Board Feet

SizeActual T × W8 ft BF10 ft BF12 ft BFTypical Use
2×41.5 × 3.5 in5.336.678.00Framing, studs
2×61.5 × 5.5 in8.0010.0012.00Joists, decking
1×60.75 × 5.5 in4.005.006.00Paneling, shelving
2×101.5 × 9.25 in13.3316.6720.00Structural beams
2×121.5 × 11.25 in16.0020.0024.00Ridge boards
4×43.5 × 3.5 in10.6713.3316.00Posts, columns

Board Foot vs Linear Foot vs Square Foot

The same 10 ft × 6 in × 1.5 in board measured in all three units:

Interactive Comparison

This shows how the same board is represented in different units.

Board Feet (volume)
7.50 BF
Linear Feet (length)
10.00 LF
Square Feet (area)
5.00 SF
MeasurementMeasuresUsed ForThickness?
Board FootVolumeLumber pricing✅ Yes
Linear FootLengthTrim, molding❌ No
Square FootAreaFlooring, plywood❌ No

Why Use Our Board Foot Calculator?

⚡

Instant Results

Board footage and cost calculated the moment you type.

🎯

Accurate Formula

The same formula used by sawmills and lumber yards.

📱

Mobile Friendly

Calculate at the lumber yard on any device.

🪵

Built for Woodworkers

Designed for cabinetmakers, furniture builders, and contractors.

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Cost Estimator

Get total project cost instantly with price per BF.

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Multi-Unit Support

Feet, inches, meters, cm, and mixed units.

Who Uses a Board Foot Calculator?

🔨

Woodworkers

Cabinetmakers and hobbyists use board foot calculations every time they buy hardwood.

🏗️

Contractors

Framing crews estimate material for residential and commercial construction projects.

🪑

Furniture Makers

Premium furniture requires precise board footage for walnut, cherry, and maple budgets.

🛠️

DIY Builders

Decks, shelves, and garden beds — calculate the right lumber amount the first time.

🌲

Lumber Dealers

Sawmills and brokers verify invoices and hardwood orders down to the decimal.

Board Foot in Logs — Doyle Rule

Estimate usable lumber yield from raw logs using the Doyle Log Rule, the most common scaling system in the eastern United States.

Interactive Doyle Rule Calculator

12 in Doyle Rule ((D−4)÷4)² × L 64 BF ((12−4)÷4)² × 16

Frequently Asked Questions

How do you calculate board feet?

Use the formula: Board Feet = Length (ft) × Width (in) × Thickness (in) ÷ 12. Measure actual dimensions and multiply by piece count.

How many board feet in a 2×4?

An 8-foot 2×4 = 5.33 BF (nominal). Using actual dimensions (1.5 × 3.5 in), about 3.50 BF.

Board foot vs cubic foot?

1 board foot = 144 in³. 1 cubic foot = 1,728 in³. So 1 cubic foot = 12 board feet.

What is board foot insulation?

Same 144 in³ concept applied to spray foam insulation — a 1 ft × 1 ft × 1 in slab.

How much does oak weigh per board foot?

Red oak: 3.08–3.58 lbs/BF. White oak: 3.42–3.92 lbs/BF (air-dried).

Can square feet be converted to board feet?

Yes: Board Feet = Square Feet × Thickness (in). Without thickness, conversion is impossible.

Why divide by 12?

It normalizes length (feet) with width and thickness (inches). The all-inches formula divides by 144.

How accurate is this calculator?

Exact industry-standard formula, accurate to two decimal places. Real accuracy depends on measurement precision.

Accuracy & Disclaimer

This calculator uses the industry-standard board foot formula. Actual lumber dimensions vary with milling, moisture, and surfacing. Always measure boards yourself, add 10–15 % waste, and confirm pricing with your supplier. For informational and planning purposes only.

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Instant, accurate board foot and cost estimates — at the workshop, the lumber yard, or from the couch.

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