How to estimate board feet
A board foot is 144 cubic inches: 1 in × 12 in × 1 ft. List each lumber item with nominal thickness, width, length and quantity, and the calculator totals board feet, thousand board feet (MBF), linear feet and cost.
- Nominal dimensions
- Board feet and MBF
- Linear feet
- Cost per MBF
1 · Lumber Nominal dimensions
2 · Price
One board foot is 144 cubic inches (1 in × 12 in × 12 in). Lumber is tallied on nominal dimensions (a 2×4 counts as 2 in × 4 in).
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Nominal dimensions, not actual
Board footage is calculated from nominal dimensions. A 2×4 is sold as 2 in × 4 in even though it dresses to about 1½ in × 3½ in. That convention matters because lumber is priced per thousand board feet (MBF), and the price assumes nominal sizes. For each item: thickness (in) × width (in) × length (ft) ÷ 12 × quantity.
- 2×4 × 8 ft: 2 × 4 × 8 ÷ 12 = 5.33 board feet.
- 2×10 × 16 ft: 2 × 10 × 16 ÷ 12 = 26.67 board feet.
- 4×4 × 10 ft: 4 × 4 × 10 ÷ 12 = 13.33 board feet.
- 1×6 × 12 ft: 1 × 6 × 12 ÷ 12 = 6 board feet.
Board feet, MBF and cost
| Size | Board feet per linear foot |
|---|---|
| 2×4 | 0.667 |
| 2×6 | 1.000 |
| 2×8 | 1.333 |
| 2×10 | 1.667 |
| 2×12 | 2.000 |
| 4×4 | 1.333 |
| 6×6 | 3.000 |
Framing, forms and blocking
Commercial estimators run into board feet on wood framing packages, concrete formwork lumber, temporary protection, blocking and backing, and timber elements. In each case the quantity starts as a count and length from the drawings, converted to board feet for pricing. Keeping your takeoff in counts and lengths by size, and converting at the end, makes it easy to re-price when lumber moves.
RenderDraw's AI takeoff proposes counts and lengths from plans and details with their sheet attached, which is the input the board-foot conversion needs.
Spend your hours on scope and price, not re-counting.
RenderDraw's AI takeoff reads drawings, schedules and specs, proposes quantities with the source sheet attached, and holds uncertain items for estimator review before anything is priced.
- Source on every quantity. Each count, length and area keeps its source sheet and location.
- Lowest confidence first. The review queue puts the items most likely to be wrong at the top.
- Addenda through the same review. Send the changed sheets through takeoff and estimator review, then reprice what moved.
- Approval before pricing. Nothing moves on to pricing until an estimator accepts it.
Send one plan set
Pick a real job with an addendum. Sample files stay private while RenderDraw assesses the request, and there is no obligation to proceed.
RenderDraw does not publish accuracy percentages or time-saved claims. Test it on your own plan set.
Questions estimators ask.
How do you calculate board feet?
Multiply nominal thickness in inches by nominal width in inches by length in feet, divide by 12, and multiply by the quantity.
How many board feet are in a 2×4×8?
5.33 board feet: 2 × 4 × 8 ÷ 12.
What is MBF?
Thousand board feet, the unit lumber is usually priced in. 5,333 board feet is 5.333 MBF.
Do you use actual or nominal dimensions?
Nominal for dimensional lumber pricing. Some hardwood and timber suppliers use actual dimensions; check how your supplier quotes.
Can RenderDraw take off framing lumber?
RenderDraw's AI takeoff proposes counts and lengths from drawings for review. Request a free sample takeoff.
Get the lumber list from the drawings.
Send a framing or formwork set. RenderDraw proposes lengths and counts from plans and details with their sheets, ready for your board-foot pricing.
- Upload the plans, specs and schedules, plus an addendum if you have one.
- RenderDraw reviews the set and the scope you want tested.
- We follow up with extracted quantities, flagged items and next steps.