Board Foot Calculator LogoBoard Foot Calculator

Board Foot Calculator for Lumber Buying

Enter thickness, width, length, and quantity to get board feet and cost. Add a waste allowance only when your project needs one.

Board dimensions

Choose each unit separately

Total Board Feet

4BF

Per Board

4 BF

Buying insight

Your 1 board selection at 1 in × 6 in × 8 ft is volume only. Match each required part to available board widths and lengths—BF alone does not guarantee cut-list yield.

(1 in × 6 in × 96 in × 1) ÷ 144 = 4 BF

Leave blank if you do not have a supplier quote.
$/ BF

Purchase planning allowance (optional)

Waste depends on your cut list, defects, grain, and board selection. Choose only what fits your project.

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Rough hardwood thickness

These presets change thickness only. Your width stays unchanged.

2× dimensional lumber

Choose nominal or actual before applying a size.

What you get

What does this calculator actually tell you?

It turns the sizes you enter into board feet and an optional purchase cost — no hidden conversion.

Yards quote and bill in board feet. If you mix tape measurements with billed sizes, your plan and the quote will disagree.

Wrong basis means buying too little, misreading a quote, or arguing with an invoice that used different rules.

Do it this way and you can:

  • See raw BF from the dimensions you typed
  • Add a supplier $/BF for cost without losing raw volume
  • Layer a planning allowance only when your cut list needs it

BF = thickness (in) × width (in) × length (in) × quantity ÷ 144

BF = thickness (in) × width (in) × length (ft) × quantity ÷ 12

Example: five 4/4 × 6 in × 8 ft boards

(1 × 6 × 8 × 5) ÷ 12 = 20 BF. At $8/BF, raw cost is $160. A 15% planning allowance makes the purchase target 23 BF and $184 — raw volume stays 20 BF.

Board feet measure volume, not cut-list yield. Lengths, defects, grain, and part layout can still make an order too small.

Supplier rules vary. Confirm how your invoice measures wood before you treat a quote as final.

This calculator reports the physical volume of the dimensions you enter. It does not apply NHLA commercial rounding, copy a supplier's tally rules, decide whether a quote is fair, or settle invoice disputes.

This site maintains this method note and records when it was last checked.

Method reviewed: July 20, 2026NHLA Rules for the Measurement and Inspection of Hardwood and Cypress

How do you run a purchase check?

  1. 1

    Enter the sizes that match your decision

    Enter thickness, width, length, and quantity. Choose rough, nominal, actual, or surfaced dimensions to match the question you are answering.

  2. 2

    Read raw board feet first

    Total Board Feet is the physical volume of the measurements you entered. The live formula shows the same math with your values.

  3. 3

    Add a supplier quote if you have one

    Enter the quoted price per BF to see raw cost. Leave it blank when you do not have a quote.

  4. 4

    Add a planning allowance only if needed

    Add waste for your project needs. Raw BF stays visible while Purchase Target BF includes the allowance.

Which sizes should you type in?

Match the numbers to the decision you are checking. The calculator never silently converts them.

Your board dimensions

Thickness is the thin edge, width runs across the face, and length runs along the board.

Board diagram labeled with the entered thickness, width, and lengthDiagram uses your entered measurements; not to scale.Length: 8 ftWidth: 6 inThickness: 1 in
  • Thickness: 1 in
  • Width: 6 in
  • Length: 8 ft
Diagram uses your entered measurements; not to scale.

Why does the lumberyard tally differ from your tape?

Some hardwood is billed at a standard thickness, or measured before planing. After surfacing, your tape can read smaller than the billed size.

Diagram comparing billed rough size with a thinner surfaced boardSome hardwood is measured before surfacing; confirm the yard's rules.Rough or standard billed size4/4surfacingSurfaced or finished size13/16 in

Rough or standard billed size A yard may tally from a standard thickness or a measurement taken before surfacing. Example billed reference: 4/4 (1 in standard thickness).

Surfaced or finished size Your tape measures the board after material has been removed. Example finished measurement after surfacing: 13/16 in.

Some hardwood is measured before surfacing; confirm the yard's rules.

What do rough, nominal, actual, and surfaced mean?

Pick the set that answers your question. Every dimension is used exactly as entered.

Rough dimensions
Measurements before the board is planed or jointed.
Nominal dimensions
A named trade size, such as 2×4, rather than the board's measured size.
Actual dimensions
The thickness, width, and length you physically measure.
Surfaced dimensions
Finished measurements after one or more faces have been planed.

Worked buying examples

What does a real buying decision look like?

Load an example into the calculator, then swap in your quote or boards. Raw BF stays separate from any planning allowance.

These are educational examples, not customer orders or supplier quotes.

You only have a bundle BF label?

Situation
You have a hardwood bundle label, but no list of individual board sizes.
What you enter
20 raw BF at $8/BF, plus a 15% project planning allowance.
What you get
20 raw BF costs $160.00. The planning target is 23 BF and $184.00.
Why it works this way
The label already gives raw volume. The allowance is added after that raw BF is kept visible.
What to do next
Compare raw cost with the supplier's $/BF, then decide whether your project needs the extra allowance.
Rule to reuse
Known BF is volume. It can support cost and allowance decisions without inventing board sizes.
What this does not promise
Equivalent lumber volume is not a promise of a fixed board count, width, or length.

Rough size and surfaced size disagree?

Situation
The same 8-foot 2×6 stock is discussed before and after surfacing.
What you enter
Rough basis: 2 in × 6 in × 8 ft. Surfaced basis: 1.5 in × 5.5 in × 8 ft.
What you get
The rough dimensions calculate to 8 BF; the surfaced dimensions calculate to 5.5 BF.
Why it works this way
Surfacing removes material, so a tape reading can be smaller than a rough or commercial tally basis.
What to do next
Before comparing a quote to a tape measurement, ask whether billing uses rough, surfaced, or another tally basis.
Rule to reuse
Enter the dimensions that match the decision you are checking. The calculator does not convert them for you.
What this does not promise
This example does not copy a supplier's grading or commercial tally rules. Confirm the billing basis on the quote.

Your cart has more than one board size?

Situation
Your cart has two 4/4 × 6 in × 8 ft boards and one 8/4 × 8 in × 10 ft board.
What you enter
Group one: 1 in × 6 in × 8 ft × 2. Group two: 2 in × 8 in × 10 ft × 1.
What you get
The two groups are 8 BF and 13.33 BF, for 21.33 BF total in the tally.
Why it works this way
Each size group is calculated on its own, then the tally adds their raw BF totals.
What to do next
Load the tally, replace these groups with the boards on your quote, and check each group before using the total.
Rule to reuse
A tally combines different board sizes. It is not a cut-list optimizer.
What this does not promise
A BF total still cannot confirm usable clear lengths, widths, defects, or grain for your parts.

Need a more specific lumber job next?

This page covers broad board-foot buying. Use these pages when your next job is cost, a unit conversion, log scaling, or learning the method.

Need a fuller project cost?

Converting to another unit?

Working from a log or learning BF?

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Common board-foot buying questions

Multiply thickness × width × length (all in inches), then divide by 144. For a 2×6×96 inch board: (2 × 6 × 96) ÷ 144 = 8 board feet. If length is in feet, divide by 12 instead of 144.