ToolForage.
CONSTRUCTION CALCULATOR

Board Foot Calculator

Enter one board size or add rows for a mixed lumber list. Use the dimensions on your supplier’s billing basis, then add a volume allowance and price per board foot.

Calculator

Labels amounts only; no exchange-rate conversion.
in
in
ft
%
USD
Each row: thickness in inches, width in inches, length in feet, whole board count. Up to 50 sizes.
YOUR RESULTS
Board feet including allowance44 bd ft
Board feet per board
4 bd ft
Batch board feet
40 bd ft
Estimated volume-based cost
220.00 USD
Total specified boards
10
Order volume in cubic metres
0.103828 m³

Each board = 1 × 6 × 8 ÷ 12 = 4 board feet. Batch volume = 40 board feet. Order = 40 × (1 + 10/100) = 44 board feet; material cost = 44 × 5 = 220 USD.

Board-size volume breakdown
Board-size volume breakdown
Size (in × in × ft)BoardsEach (bd ft)Batch (bd ft)
1 × 6 × 810440
Page guide

Board volume and purchasing allowance

The base batch is the volume of the specified boards. The allowance adds a percentage of that volume for purchasing estimates; it does not create a cutting list or select extra board lengths.

For a decking surface, the Deck Board Calculator counts board rows and whole stock lengths instead of volume.

The formula

Board feet per board = thickness(in) × width(in) × length(ft) ÷ 12. Batch board feet = volume per board × board count. Mixed-list volume is the sum of all row volumes; order volume = total × (1 + allowance/100).

One board foot is 144 cubic inches. Length is entered in feet, so the conversion to inches cancels part of that divisor, leaving division by twelve. The volume allowance is applied once to the entire batch before multiplying by price.

Worked example

Ten boards measuring 1 inch by 6 inches by 8 feet contain 4 board feet each, or 40 in total. A 10% volume allowance gives 44 board feet. At 5 per board foot, the estimated volume-based cost is 220.

How to use this calculator

  1. Confirm which thickness and width the supplier uses for billing.
  2. Choose one size or add one row per thickness, width, length and whole quantity. Paste rows if you already have a list.
  3. Set the shared volume allowance and price per board foot. Read live totals and the board-size breakdown.

Nominal, rough, and finished sizes

Board-foot billing can use dimensions different from the finished dimensions you measure after surfacing. Confirm the supplier’s convention before comparing prices. This calculator uses exactly the numbers entered; it does not convert a nominal 2 by 4 into a dressed section automatically.

Board feet do not describe usable cuts

Two orders can contain the same volume but have different usefulness for a project. Required lengths, knots, grain selection, saw kerf, and machining allowance can all affect usable yield. Use separate rows for different thicknesses, widths or lengths. A percentage allowance is suitable for an early quote, but verify actual stock lengths against the final cut list.

Assumptions & limitations

What this calculation assumes

  • Every row uses the stated billing dimensions; one shared price and allowance apply to the full list.

What to keep in mind

  • No log-yield rule, grading adjustment, or cutting optimization is included.

Common questions

Is a board foot the same as a linear foot?

No. A linear foot measures length alone. A board foot measures volume, so thickness and width both affect the result.

Why is my lumber invoice different?

Billing dimensions, grade premiums, minimum charges, surfacing fees, and rounding rules can differ. Match the dimensions and pricing convention on the quote.

Sources & further reading

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