Laser Settings Converter
Translate known-good settings from one laser to another. Pick the machine your settings came from, the one you're moving to, and get an equivalent power and speed — plus a safer first test and a printable test grid.
How this works
Enter your own numbers or keep our defaults. Results update as you type and are calculated on your device; nothing is sent to us. Each default value shows where it came from.
Assumptions you can change
Conversions assume the same laser type (diode→diode, CO2→CO2, fiber→fiber) and scale by energy density only. Spot size, beam quality, pulse behaviour and material batch all shift the real result — always run the test grid before a job. We start you 20% lower on energy as a safety margin (our assumption).
Short answer: keep the energy you put into the material constant. For engraving that's watts ÷ (speed × line interval), in J/mm²; for cutting it's watts ÷ speed, in J/mm. Doubling usable power means doubling speed (or halving power %). It only holds between lasers of the same type — diode to diode, CO2 to CO2, fiber to fiber — and you should start about 20 % lower and run a test grid.
Your known-good settings
= 254 LPI
Machine you're moving to
Start your first test at
80% power at 250 mm/s
That is 20 % below your known-good energy (1.6 J/mm² → 1.28 J/mm², same 0.1 mm interval). Burn it on scrap, then step up.
Dashed box: the test grid below spans 0.86–2.9 J/mm².
- Spot size differs (0.069 → 0.089 mm, manufacturer-rated). Peak intensity at full power changes about 1.2×. A bigger spot spreads energy — expect shallower, wider marks; you may need a smaller interval or more power.
Test grid for the target machine
Centred on the converted setting (80 %, 200 mm/s). Columns change power, rows change speed; stronger colour = more energy.
The SVG is drawn in real millimetres (10 mm squares), each square its own colour and id so you can give it its own layer. The CSV lists every cell's power and speed — or type the min/max into LightBurn's Material Test tool.
How the conversion works
A laser deposits heat. How deep and how dark a mark gets depends mostly on how much energy lands on each square millimeter (engraving) or on each millimeter of line (cutting). If two machines of the same type deliver the same energy density, they should produce a similar result on the same material — that's the whole idea.
Raster engraving: energy per area
Vector cutting and scoring: energy per length
Solving for the new machine
Set the target's energy equal to the source's and solve for one unknown. Keeping your power % the same gives the new speed:
Keeping your speed instead gives the new power %: p₂ = p₁ × P₁ / P₂. If that would need more than 100 %, the tool pins power at 100 % and slows down.
Line interval and LPI/DPI
Worked examples
Why you can't convert between laser types
Energy density only transfers when the material absorbs the light the same way — and absorption depends on wavelength. The same watts do completely different things at different wavelengths:
| Laser type | Wavelength | What that means |
|---|---|---|
| Blue diode | ~445–455 nm | Absorbed well by dark, organic materials. Passes straight through clear acrylic and clear glass; white and pale materials reflect much of it. |
| Fiber / IR | 1,064 nm | The choice for bare metal marking. Wood and most plastics absorb it poorly; clear acrylic is largely transparent to it. Pulsed sources — results also depend on frequency and pulse width. |
| CO2 | 10,600 nm (10.6 µm) | Absorbed by almost all organics, acrylic (including clear), glass and stone. Bare metal reflects it — metals need a marking compound. |
That's why the tool blocks diode → CO2 or CO2 → fiber conversions. Use the target machine's own material library, then refine with a test grid.
Assumptions and limits
- Same energy ≠ same result across laser types: materials absorb 455 nm (blue diode), 1,064 nm (fiber) and 10.6 µm (CO2) very differently — e.g. clear acrylic passes blue light but absorbs CO2 light, and fiber lasers are the best choice for bare metal.
- Spot size changes power density (W/mm²). A smaller spot at the same watts engraves deeper and needs a smaller line interval; a bigger spot spreads the same energy.
- Only convert within the same laser type (diode→diode, CO2→CO2, fiber→fiber). Cross-type conversions are shown for reference only.
- Power % is not perfectly linear: diode drivers and CO2 tubes (which have a minimum firing power) respond differently at low settings.
- Pulsed fiber (and MOPA) results also depend on frequency and pulse width, which this formula ignores.
- Use the machine’s real optical output power. Some listings quote electrical input or “equivalent” power; that will make conversions wrong.
- Always run a small power/speed test grid on scrap of the exact material before a paid job.
- Energy-per-area/length models ignore thermal diffusion: at very slow speeds heat spreads and chars more than the formula predicts.
- Acceleration at line ends is ignored; real average speed on small raster jobs is below the set speed.
- Fiber typical spot size (0.03 mm) is an assumption pending measurement.
- Machine power, spot size and max speed come from manufacturer spec sheets (linked on each product page); we have not measured them yet. For dual-laser machines, each source is listed separately.
- The "first test" suggestion delivers 20 % less energy than your known-good setting. That margin is our conservative rule of thumb, not a physical constant.
Using the test grid
- Download the SVG and import it into your laser software at 100 % scale (the file is in millimeters: 10 mm squares).
- Give each square its own layer or use the CSV to set each cell's power and speed. In LightBurn, the built-in Material Test tool accepts the same min/max power and speed ranges shown in the CSV header.
- Run it on scrap of the exact material and finish you'll sell. Pick the lightest square that looks right — the lowest energy that works is kinder to your laser and your edges.
Related guides
Sources
Every spec and number on this page links back to where it came from.
- LightBurn Docs — 5 Steps to Perfect Image Engravings (line interval ↔ DPI)
- LightBurn Docs — Interval Test
- Epilog Laser — What are the wavelengths of the laser sources?
- xTool Support — S1 20W & 40W laser module comparison (spot size)
- xTool — Laser machine comparison chart (tech specs)
- xTool — The Complete Laser Cutting Materials List (which laser suits which material)
- xTool Support — Essentials When Processing Acrylic (blue light passes clear acrylic)
- MIT EHS — Laser Cutter Safety Guidance (Jan 2024, PDF)
- U.S. FDA — Laser Products and Instruments (laser hazard classes)
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New research, price changes and test results as they land. Written for people who make things to sell.