How many board feet in a 2×4×12?

A 12-foot 2×4 is 8 BF: (2 × 4 × 12) ÷ 12 = 8. A 16-foot 2×4 is 10.67 BF: (2 × 4 × 16) ÷ 12 = 10.67.

Should I enter rough, nominal, actual, or surfaced dimensions?

Enter the dimensions that match your decision. Use actual measurements for wood in hand, nominal sizes for a trade-size estimate, and the supplier's billed dimensions when checking a quote. The calculator never changes them silently.

How many board feet in 4/4 lumber?

4/4 means 1 inch thick. A 6-inch wide, 8-foot long 4/4 board is 4 BF: (1 × 6 × 96) ÷ 144 = 4. The fraction (4/4, 6/4, 8/4) is thickness in quarter-inches.

How many board feet in 8/4 lumber?

8/4 means 2 inches thick. A 6-inch wide, 8-foot long 8/4 board is 8 BF: (2 × 6 × 96) ÷ 144 = 8 — double the same face size in 4/4.

Why does the supplier tally differ from my measurement?

A supplier may tally rough lumber at a standard thickness, before surfacing, or under commercial measurement rules. This calculator uses the dimensions you enter without those rules, so confirm the billing basis with the supplier.

How much extra lumber should I buy?

There is no single waste factor for every job. Defects, grain matching, board lengths, and cut layout all matter. Start at 0%, then add an allowance only when your project plan supports it.

What does a 10 BF or 20 BF bundle look like?

A BF total describes volume, not fixed boards. Use known-BF mode to compare the same volume as 4/4 × 6 in, 4/4 × 8 in, and 8/4 × 6 in lumber. The actual bundle can mix widths, lengths, and board counts.

Can enough board feet still be the wrong order for my project?

Yes. Board feet do not guarantee that available lengths, widths, grain, and clear sections fit your cut list. Check part layout and defects before ordering.

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

Thickness

Width

Length

Quantity

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

Supplier price per BF (optional)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.

Custom waste (0–50%)

Share this result

Rough hardwood thickness

These presets change thickness only. Your width stays unchanged.

2× dimensional lumber

Choose nominal or actual before applying a size.

After you calculate

How do you get this board-foot number?

Multiply thickness (in) × width (in) × length (ft), then divide by 12. An 8-foot 2×4 is 5.33 BF. A 10-foot 2×4 is 6.67 BF.

2×4×8 ft = 5.33 BF — (2 × 4 × 8) ÷ 12
2×4×10 ft = 6.67 BF — (2 × 4 × 10) ÷ 12

Those use the named 2×4 size. If you measured the board, type the tape reading instead.

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

What if the lumberyard number does not match?

Yards quote and bill in board feet. If you mix a tape measurement with a billed size, 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

How do you run a purchase check?

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
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
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
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.

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.

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?

Lumber cost estimatorAdd tax, delivery, and several pricing inputs for a fuller project budget.

Converting to another unit?

Working from a log or learning BF?

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Common board-foot buying questions

Use ÷ 12 when length is in feet. Use ÷ 144 when thickness, width, and length are all in inches. Same 2×4×8: (2 × 4 × 8) ÷ 12 = 5.33 BF, or (2 × 4 × 96) ÷ 144 = 5.33 BF.