1 Measure Kerf
2 Compensate
3 Box Joints
๐ฌ Measure Your Kerf
Cut a rectangle and measure the actual cut piece vs. the designed size. The difference is your kerf.
Fiber Metal
Fiber Deep
CO2 Wood 3mm
CO2 Wood 6mm
CO2 Acrylic 3mm
CO2 Acrylic 6mm
CO2 MDF 6mm
Diode Plywood
CO2 Leather
Method A โ Direct measurement
Method B โ Measure from test cut
Calculated kerf: 0.15 mm
Tip: For best accuracy, cut 10 strips side by side and measure the total gap. Divide by 10 for average kerf.
Tip: For best accuracy, cut 10 strips side by side and measure the total gap. Divide by 10 for average kerf.
Method C โ Multi-cut average (most accurate)
Average kerf: 0.15 mm
๐ Kerf Compensation
Enter your design dimensions and we'll calculate the compensated sizes to achieve a perfect fit.
0.15
Active kerf mm
0.075
Offset (kerf/2) mm
Tight fit: Full kerf compensation โ pieces will press together snugly. Ideal for inlays and puzzle pieces.
Design dimensions
| Part | Original | Cut Path | Actual Result | ฮ |
|---|
How to apply in LightBurn: Use the compensated "Cut Path" dimensions in your design. The laser removes material (kerf), so cut paths are slightly larger for outer cuts and slightly smaller for inner cuts (holes).
Outer cut: +offset per side โ Inner cut (hole): โoffset per side
Outer cut: +offset per side โ Inner cut (hole): โoffset per side
๐งฉ Box Joint / Finger Joint Calculator
Calculate kerf-compensated finger widths for perfect interlocking joints.
3 (thick)25 (fine)
-
Finger width mm
-
Compensated width mm (tab)
-
Slot width mm (cut)
-
Resulting gap mm per side
The tab (protruding finger) cut path is slightly wider to compensate for kerf.
The slot (receiving gap) cut path is slightly narrower.
This ensures a perfect interlock after the laser removes material.
The slot (receiving gap) cut path is slightly narrower.
This ensures a perfect interlock after the laser removes material.
๐จ Interactive Diagram
๐ Typical Kerf Values
| Laser + Material | Typical Kerf |
|---|---|
| Fiber โ Thin metal (0.5mm) | 0.03 โ 0.06 mm |
| Fiber โ Metal engraving line | 0.05 โ 0.10 mm |
| CO2 โ 3mm Plywood | 0.12 โ 0.18 mm |
| CO2 โ 6mm Plywood | 0.18 โ 0.28 mm |
| CO2 โ 3mm Acrylic | 0.10 โ 0.15 mm |
| CO2 โ 6mm Acrylic | 0.15 โ 0.22 mm |
| CO2 โ MDF 3mm | 0.15 โ 0.22 mm |
| CO2 โ MDF 6mm | 0.22 โ 0.30 mm |
| CO2 โ Leather | 0.06 โ 0.12 mm |
| CO2 โ Cardboard | 0.10 โ 0.15 mm |
| Diode โ 3mm Plywood | 0.08 โ 0.15 mm |
| Diode โ 3mm Dark acrylic | 0.10 โ 0.18 mm |
Factors affecting kerf: Laser power, speed, focus, material type, material thickness, air assist pressure, lens focal length, and beam quality. Always measure your own kerf for precision work!