Board Foot Calculator
Convert a lumber list into board feet: enter the nominal thickness, width, and length, the piece count, and optionally a price per board foot, and get total BF and cost — then print it as a material order sheet. Board footage runs on nominal (name) sizes, the convention mills and yards price by, even though the dressed board in your hand is smaller. Free, no login.
Lumber (nominal)
Board Feet
BF = (T × W × L) ÷ 12, using nominal dimensions — actual (dressed) sizes are smaller.
Board Foot Calculator — Material Order Sheet
Prepared with NORDIX — nordixhq.com/tools/board-foot-calculator
| Lumber: 2" × 6" × 8 ft (nominal) | Quantity: 10 | Price: — |
| Item | Qty | Unit | Notes |
|---|---|---|---|
| 2×6 lumber, 8 ft | 10 | pieces | nominal dimensions |
| Board feet | 80 | BF | BF = (T × W × L) ÷ 12 |
Method: board feet from nominal thickness × width × length ÷ 12, times quantity. Planning figures — actual (dressed) sizes are smaller than nominal; confirm grade, species, and pricing with the supplier.
How this calculator works
A board foot is 144 cubic inches of lumber — one square foot, one inch thick — figured on nominal dimensions:
BF = (thickness in × width in × length ft) ÷ 12 × quantity
The nominal convention matters: a 2×6 counts as 2 in. × 6 in. in the math even though the dressed S4S board measures 1-1/2 × 5-1/2 in. — the nominal-to-dressed relationship for softwood lumber is standardized in US Product Standard PS 20 (thickness and width each lose 1/2" up to 6" nominal, 3/4" at 8" and wider). Board footage on name-size is how the trade prices, so that is what this calculator uses; if you are buying rough-sawn stock quoted at true dimensions, enter the actual measurements instead. Two shortcuts that fall out of the formula: a 2×6 and a 1×12 each carry exactly one board foot per foot of length.
Worked example
Ten 2×6s, 8 ft long:
- Per piece: (2 × 6 × 8) ÷ 12 = 8 BF.
- Total: 8 × 10 = 80 BF.
- Cost: at $1.20/BF that is $96.00 — enter the price to see it; leave it blank to skip cost.
Enter the same list above (2 × 6 × 8 ft, quantity 10) to reproduce it. Remember the result is net BF — add a waste factor (10–15% on dimensional lumber, more on hardwood) before ordering.
Reference: board feet per piece (nominal 2× lumber)
Computed from the same formula the calculator uses — BF per single piece by nominal size and length.
| Size | 8 ft | 10 ft | 12 ft | 14 ft | 16 ft |
|---|---|---|---|---|---|
| 2×4 | 5.33 | 6.67 | 8 | 9.33 | 10.67 |
| 2×6 | 8 | 10 | 12 | 14 | 16 |
| 2×8 | 10.67 | 13.33 | 16 | 18.67 | 21.33 |
| 2×10 | 13.33 | 16.67 | 20 | 23.33 | 26.67 |
| 2×12 | 16 | 20 | 24 | 28 | 32 |
Frequently asked questions
How do you calculate board feet?
A board foot is 144 cubic inches of lumber: nominal thickness (in.) times nominal width (in.) times length (ft), divided by 12. A 2x6 that is 8 ft long works out to (2 × 6 × 8) ÷ 12 = 8 board feet. This calculator applies that formula, multiplies by quantity, and — if you enter a price per board foot — returns the total cost.
Do I use nominal or actual dimensions for board feet?
Nominal. Board footage is figured on the name-size of the lumber — a 2x6 counts as 2 in. by 6 in. even though it measures 1-1/2 in. by 5-1/2 in. after surfacing. That is the convention mills and lumberyards price by, and it is what this calculator uses. If you are buying rough-sawn stock quoted at true dimensions, enter the actual measurements instead.
How many board feet are in a 2x4x8?
(2 × 4 × 8) ÷ 12 = 5.33 board feet. A 2x6x8 is exactly 8 BF, a 2x8x8 is 10.67 BF, and a 2x10x10 is 16.67 BF. A shortcut worth remembering: any 2x6 or 1x12 carries exactly one board foot per foot of length.
What is the difference between a board foot and a lineal foot?
A lineal foot measures length only, regardless of the size of the piece; a board foot measures volume, so thickness and width count too. Ten feet of 2x12 is 10 lineal feet but 20 board feet. Framing lumber is usually sold by the piece or by lineal foot, while hardwood and rough-sawn stock is sold by the board foot — which is when this calculator earns its keep.
Should I add waste to a board-foot takeoff?
Yes — the calculator returns net board feet, so add a waste factor on top. As an estimating rule of thumb, 10–15% covers cutting loss and culls on dimensional lumber, and hardwood jobs often carry 20–30% or more because lower grades yield less clear material. Adjust for how much of each board your cut list actually uses — lots of short pieces waste less than long clear runs.
Method: BF = (nominal T × W × L) ÷ 12 × quantity — pure geometry on the nominal-size convention, with dressed (actual) sizes per US PS 20 (a 2× measures 1-1/2" thick; widths run 1/2" under nominal to 6", 3/4" under at 8" and wider). The result is net board footage: waste, grade yield, and culls are not included — add an allowance before ordering, and confirm species, grade, and pricing with the supplier. Lineal-foot and piece-count pricing are different conventions; ten feet of 2×12 is 10 lineal feet but 20 board feet.
Pair with the Stud & Framing Calculator to build the piece count for a wall, the Decking Calculator for deck-board takeoffs, or the Lumber & Panel Price Tracker to time the buy.