LUMBER CUT LIST
About this calculator
This lumber cut calculator tells a framer or finish carpenter exactly how many boards to buy when every cut is the same length — wall studs, blocking, cripples, jack rafters, fascia returns, deck balusters, fence pickets. Pick the stock length you can buy at the lumberyard, enter the length each cut needs to be, set how many cuts the job calls for, and the calculator subtracts a saw kerf (default 1/8") from each cut. The output is the cuts you can get per board, total boards needed (rounded up), and the leftover waste per stick. For a mixed cut list, run the calculator separately for each unique length and add the boards together.
How to use this calculator
Pick the stock board length you can buy — 8-foot is the most common at lumberyards, but longer stock cuts down on waste for repetitive cuts. Enter the cut length in inches (a pre-cut wall stud for an 8-foot ceiling is 92⅝ inches; a 16" o.c. wall cripple is 14½ inches). Set the total number of cuts you need.
The kerf is the saw blade width — 1/8 inch is standard for circular saws and miter saws; thin-kerf framing blades run 3/32 inch. The calculator returns cuts per board, total boards needed (rounded up), and waste percentage. For mixed cut lists, run the calculator separately for each unique length and sum the results.
Worked example
For 30 wall studs at 92⅝" each, cut from 16-foot (192") stock with a 1/8" kerf:
Cuts per board: ⌊192 ÷ (92.625 + 0.125)⌋ = ⌊192 ÷ 92.75⌋ = 2 cuts per board. Boards needed: ⌈30 ÷ 2⌉ = 15 boards.
Waste per board: 192 − (2 × 92.75) = 6.5 inches per board (basically scrap). Total waste: 15 × 6.5 = 97.5 inches = 8.1 ft of unusable stock from 240 ft purchased = 3.4% waste.
If you'd bought pre-cut studs (92⅝" sold individually), you'd skip the cutting waste entirely — but pre-cuts are 10–15% more expensive per linear foot than buying long stock.
For 50 fence pickets at 72" each from 96" stock: 1 cut per board (one 72" picket plus 23⅞" leftover that's mostly scrap). 50 boards needed.
Common mistakes & waste factors
Forgetting kerf. The saw blade removes 1/8" of material with each cut. On a board with 4 cuts, that's ½" of lost material — can be the difference between fitting one more cut or not.
Buying stock just barely long enough. A 96" board minus three 30" cuts minus three kerfs leaves 5⅝" of waste per board. Bumping up to 120" stock might give you 4 cuts per board with less total waste.
Mixing cut lengths in the calculator. The calculator handles ONE cut length at a time. For a job with 30 studs at 92⅝" plus 60 cripples at 14½", run them separately and add the boards.
Ignoring grain orientation for finish work. The calculator handles dimensional cuts only. For trim or cabinet stock where grain matters (continuous grain across multiple pieces from one board), waste rates run 30–50% instead of 5–10%.
Rules of thumb
Standard kerf: 1/8" (most circular and miter saws). Thin-kerf framing blade: 3/32".
Pre-cut studs: 92⅝" (8-ft wall), 104⅝" (9-ft wall), 116⅝" (10-ft wall).
Stud cuts that maximize 8-ft stock: 47⅞" (2 per board) or 31½" (3 per board) — cripple lengths.
Stud cuts that maximize 16-ft stock: 95⅞" (2 per board) or 63⅞" (3 per board).
For mixed cut lists, run separately and sum. Mixed cuts also reduce optimization — consider hand-laying with chalk before cutting.
Common questions
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