Laser Kerf & Press-Fit Calculator

Measure one test cut. Turn it into an offset you can actually use.

Enter the square you designed and what the cut-out piece measured. Add the matching hole if you measured it. Get estimated full kerf, per-edge offset and a nominal slot starting width.

Designed square (mm)

Measured piece (mm)

Measured hole (mm, optional)

Material thickness (mm, optional)

Extra slot clearance (mm; 0 = nominal material thickness)

ESTIMATE

Estimated kerf

A useful calibration workflow

Measure the same material and settings you plan to use.

Start with a simple square at a known design size and cut it using the material, thickness, focus and power/speed settings you want to calibrate. After the piece has cooled, measure the cut-out piece with a suitable measuring tool. If practical, measure the opening as well. The difference between the designed size and those measurements provides an estimate of the material removed by the beam.

A piece that measures smaller than designed gives one kerf estimate. A matching opening that measures larger gives another. When both are available, this calculator averages them and warns when they disagree strongly, because disagreement is a reason to re-measure rather than blindly trust a single number.

Kerf and press fit

An offset is a starting point, not a universal material constant.

Full kerf is the approximate width removed by the cut. A centered path therefore corresponds to roughly half that amount on each edge. For a slot cut to a nominal design width, the finished opening becomes roughly one full kerf wider, so the calculator subtracts the estimated kerf from material thickness plus any extra clearance you choose.

Real press fit also depends on material compression, grain, humidity, measurement tolerance and machine repeatability. Test the result physically before committing a full sheet. If you need to verify SVG dimensions before cutting the calibration file, use SVG Size & Units Checker.