Material-Cut Calculator

By Dom Hartley · Founder

Whether a laser can cut a material is not about the box-watt number — it's about the machine type, the optical wattage, the material and its thickness. I built this after watching too many makers buy a laser that could never cut what they wanted. Pick your material and thickness, tell it your machine type and optical wattage, and it gives you a clear verdict — can it cut, only engrave, or neither — plus speed and passes guidance. It's drawn from manufacturer cut charts and laser physics, not bench tests.

Safety first: wear laser glasses rated for your machine's specific wavelength and optical density, run proper fume extraction ducted outside, never cut materials that release toxic gas (such as PVC/vinyl), and never leave a running laser unattended. Always follow your machine's manufacturer instructions.

Will your machine cut it?

Diode and CO2 cut completely different materials.

The optical (output) watts — not the big box/input number.

The material decides which machine type can touch it.

For marking/engraving, thickness barely matters — enter 0 or leave blank.

How this is calculated
  • Wavelength first. A diode (~450nm) is absorbed by wood, leather, paper and dark/coated stock, but passes straight through clear acrylic and reflects off bare metal — so no diode wattage cuts those. A CO2 (~10.6µm) cuts acrylic (including clear), wood, leather and paper, but does not mark bare metal without a marking spray and does not cut metal at hobby power.
  • Then optical wattage vs thickness. Within a workable material, the verdict and pass guidance scale with optical wattage and thickness, using rough cut-capability bands derived from manufacturer cut charts (e.g. a ~20W optical diode cuts thin plywood in a few passes; a ~40W CO2 cuts thicker acrylic and wood). More passes, not more single-pass power, is how you get clean cut-through on thicker stock.
  • Verdict meanings. Can cut = the type and power can cut through at the thickness given. Engrave only = it can mark/engrave but not cut through (too thick for the power, or a material the type can only mark). Won't work = wavelength makes it impossible (clear acrylic on a diode; bare metal cutting on either type).
  • Speed and passes are guidance, not gospel. Real settings depend on your exact machine, focus, air assist and material batch — always run a material test grid on scrap and record what works.

These are capability estimates from manufacturer cut charts and the physics of optical wattage and material absorption — not bench tests of any specific machine. Test on scrap, follow your machine's manufacturer instructions, run proper extraction, and never leave a running laser unattended.

Found out your machine can't cut what you need? Weigh the two laser types in the diode-vs-CO2 chooser, or see real machines in the best laser engravers for wood guide and the best desktop CO2 laser cutters.

Affiliate note: our guides earn from qualifying Amazon purchases at no cost to you. Full disclosure. Specs are verified against manufacturer details and current listings — no hands-on testing claims.