How to use this calculator
- Enter the finished part length. Use the final length for each repeated piece, after trimming.
- Set quantity and cut count. Count how many finished parts are needed and how many kerfs should be charged to the layout.
- Enter blade kerf and trim allowance. Use the measured blade or cutter width, plus any end trim needed to square the stock.
- Check stock length and yield. Read required stock length, stock pieces needed, remaining offcut, length yield and kerf cost.
How it works
Kerf loss is the simplest part of a cut plan: each charged cut removes one blade-width strip of material.
L_kerf = N_cut x k
The required stock length for a repeated part run is the finished part length times quantity, plus kerf loss and any end-trim allowance:
L_req = N_part x L_part + L_kerf + e
The calculator then compares that required length with the stock length you buy, so it can show stock pieces needed, offcut length and length yield. It is intentionally a linear screen, not a sheet nesting or mixed board optimizer.
Worked example
Verified against the live calculator
Suppose you need 12 pieces at 18 in each from
8 ft boards. With a 1/8 in blade kerf,
12 charged cuts and a 1/2 in end trim, the
required length is 216 + 1.5 + 0.5 = 218 in. That takes
3 stock lengths, leaves about 70 in of
offcut and loses 1.5 in to kerf.
Frequently asked questions
What is saw kerf?
Saw kerf is the width of material removed by a saw blade, router bit, abrasive wheel or other cutter. Kerf loss is the kerf width multiplied by the number of cuts you charge to the layout.
Should cut count equal the number of pieces?
Often yes, especially when you trim one end first and then cut each finished piece to length. If a layout truly shares an uncut starting edge, the charged cut count may be one less than the finished piece count.
Is this the same as a cut list calculator?
No. This page isolates kerf width and linear cut loss for repeated pieces. Use the cut list calculator when mixed lengths, board packing, overage or board-foot takeoff controls the material buy.
Does it work for metal or abrasive cutting?
Yes for simple linear loss. Enter the actual cutter width and stock length. Heat-affected zones, burr allowance, squaring cuts and workholding loss still need shop judgment.
Method & assumptions
- Kerf loss is cutter width multiplied by the charged cut count.
- Finished part length is multiplied by the rounded finished-piece quantity.
- End trim is charged once to the overall repeated-part run.
- Stock pieces needed is a length-only count before detailed board packing.
- Does not model mixed part lengths, defects, grain direction, rough/surfaced size changes, miters, clamp waste, blade runout or sheet nesting.
- For the broader exact search path, use the kerf calculator; for bend spacing, use the kerf bending calculator.
- For detailed board packing, use the cut list calculator. For a simple lumber volume tally, use the board feet calculator.