Kerf is the width of material removed by the saw blade during each cut — essentially the sawdust path. A typical circular saw blade has a kerf of about 1/8″ (0.125″), while band saws may be as thin as 1/16″ (0.0625″). Chain saws have wider kerfs around 1/4″–3/8″. For a log cut into 8 boards, an 1/8″ kerf means 1 full inch of wood lost to sawdust. Accounting for kerf is critical for accurate yield calculations and maximizing usable lumber.

Our optimizer uses an exhaustive search algorithm with smart pruning to evaluate thousands of possible combinations of your target board lengths. It considers the log length, saw kerf width, and all target lengths (with quantities) to find the combination that maximizes total usable lumber while staying within the physical constraints of the log. For very large sets of targets, it employs heuristic optimization to deliver results quickly. The algorithm accounts for kerf loss on every cut, giving you a realistic yield estimate.

Rough-sawn lumber is cut directly from the log and has not been planed or jointed — it's typically 1/8″ to 1/4″ oversized in all dimensions compared to finished (surfaced) lumber. For example, a rough-sawn 2×4 actually measures about 2″×4″, while a finished 2×4 (S4S) measures 1.5″×3.5″. When using this optimizer, input the target finished length and consider adding extra for rough-sawn if you plan to surface the boards later. You can account for this by adding a small margin to each target length.

The number depends on your log length, target board lengths, and kerf width. For a 16-foot log (192″) with a 1/8″ kerf: you could get eight 24″ boards (192″ minus 8×0.125″ kerf = 191″ used of 192″), or four 48″ boards, or combinations like three 60″ boards plus one 12″ board. Our optimizer tests all viable combinations to find the one that yields the maximum total board length. For logs with irregular shapes or taper, actual yield may be lower — this tool assumes a straight, cylindrical log optimized for length only.

Two factors reduce utilization: kerf loss (each cut removes blade-width material) and remainder waste (the leftover piece too short for any target length). For example, with a 192″ log, 1/8″ kerf, and targets of 30″ each: you can fit six 30″ boards (180″ of lumber + 6×0.125″=0.75″ kerf = 180.75″ total), leaving 11.25″ of waste. Utilization = 180/192 = 93.75%. The optimizer minimizes this residual waste by exploring all combinations, but some waste is often unavoidable unless target lengths divide the log perfectly.

Absolutely! While the tool displays inches by default, you can use any unit consistently — just enter all values in the same unit (centimeters, millimeters, or meters). For example, enter a 400cm log with a 3mm kerf (0.3cm) and target lengths in centimeters. The math works identically. Key rule: use the same unit for log length, kerf width, and all target lengths. The optimizer calculates proportions, so unit choice doesn't affect the optimal pattern — only the input numbers matter.

Saw Type	Typical Kerf	Best For
Band Saw (thin blade)	0.04″–0.063″ (1–1.6mm)	Precision resawing, veneer
Band Saw (standard)	0.063″–0.125″ (1.6–3.2mm)	General sawmilling
Circular Saw (table saw)	0.098″–0.125″ (2.5–3.2mm)	Cross-cutting, ripping
Chain Saw (milling)	0.25″–0.375″ (6–9.5mm)	Portable/Alaskan milling
Frame Saw / Gang Saw	0.08″–0.12″ (2–3mm)	High-volume production

Always measure your actual blade kerf — worn or sharpened blades may differ from manufacturer specs.

This optimizer assumes a straight, defect-free cylindrical log for length optimization. For logs with defects: (1) measure and deduct the defective portions from your effective log length before inputting; (2) treat the log as multiple shorter clear sections and optimize each separately; (3) for tapered logs, use the small-end diameter for width calculations (separate from length optimization). For severely irregular logs, consider a 3D scanning system or consult a professional sawyer for the best breakdown strategy.

Best practice: cut longest boards first. If you cut short boards first and make a mistake, you may ruin the opportunity for longer boards. By cutting the longest pieces first, any errors or defects discovered mid-cut can be salvaged into shorter target lengths. The optimizer's suggested cut sequence prioritizes longer boards at the start of the log, which aligns with this practical approach. Always mark your cut lines clearly and double-check measurements before each cut.

This tool focuses on single-log length optimization — finding the best way to cut one log into boards of desired lengths. A full cut-list optimizer (or cutting stock problem solver) handles multiple logs/boards simultaneously, often with different stock lengths, quantities, grain direction constraints, and cost optimization across an entire project or production run. For hobbyists and small sawmill operations, single-log optimization is usually sufficient. For larger operations processing many logs, consider specialized sawmill software like WoodMizer's or dedicated cut-list applications.