Lumber Calculator
Estimate board quantity and total linear footage.
Project details
Enter your measurements below.
Enough total footage does not always mean the right boards for the cut list
This calculator handles a common purchasing question: if a project needs a certain total linear footage and boards come in fixed stock lengths, how many boards should be purchased? It applies the allowance you enter, divides by stock length and rounds up. That works well for trim, rails, blocking and other jobs where pieces can be cut from stock flexibly. It is less useful when the project requires several long, unbroken pieces; a pile of short boards can have enough total footage but still fail the cut list.
Linear material quantity, not board-foot volume.
Use the actual length you plan to buy.
Long required pieces can control stock selection even when total footage is sufficient.
How to use the Lumber Calculator
- Add the required lengths of all pieces that can realistically share the same stock size.
- Choose the stock board length available from the supplier.
- Apply a cut allowance that reflects saw kerf, defects and the likelihood of reusing offcuts.
- Divide adjusted linear footage by stock length and round up, then test the result against the longest pieces in the cut list.
Why this is a linear-footage tool
Thickness and width do not affect the board count when every required piece uses the same stock profile; only the lengths and cutting efficiency matter.
Use the total together with a cut list
Before ordering, verify that the proposed stock lengths can produce the long pieces and that the offcut assumptions are realistic.
Worked example: 95 linear ft from 12 ft boards
- Required run
- 95 ft
- Allowance
- 8%
- Adjusted footage
- 102.6 ft
- Stock length
- 12 ft
102.6 ÷ 12 = 8.55, so the pure footage estimate rounds to nine 12-foot boards. If the cut list contains ten separate 10-foot pieces, however, nine boards would still be insufficient despite the footage math.
Practical planning tips
Group parts by stock cross-section before adding lengths; a 2×4 and 2×6 should not share one linear total.
Check the longest required cut before choosing stock length.
Reuse offcuts only when they are long enough and suitable for later pieces; do not assume perfect nesting.
For expensive hardwood sold by board foot, use board-foot pricing alongside the cut-list plan.
Common mistakes to avoid
Adding every lumber piece in the project together even when widths/thicknesses differ.
Choosing stock length solely from the lowest price per foot without checking long-piece requirements.
Assuming all saw kerf and defects are covered by a tiny allowance on a complex cut list.
Confusing linear footage with board feet.
Lumber Calculator FAQs
What is linear footage?+
It is simply total length. A 10-foot board contributes 10 linear feet regardless of its width or thickness.
How much lumber waste should I add?+
It depends on the cut list, defects and offcut reuse. A detailed cut optimization can be better than one blanket percentage for expensive material.
Why can total footage be enough but the board count still fail?+
Because required pieces have minimum lengths. Short stock cannot always be combined to make one long unbroken part.
When should I use the Board Foot Calculator instead?+
Use board feet when lumber is bought or priced by volume, particularly rough-sawn hardwood.