G-code viewer

Paste a program to see the toolpath in plan and side view, its extents and end point, and an estimated run time. Nothing is uploaded: it all runs in your browser.

A preview, not a simulation of your machine. The run time is an estimate: it ignores acceleration, look-ahead, tool changes and overrides, so real machines usually take longer. Cutter and nose compensation, tool length, G28/G53 and lathe canned cycles are not applied. Always prove a program on the machine’s own graphics and with a dry run. See the terms of use.

How it works, guides and notes

What it reads

G0, G1, G2 and G3 (centre I/J/K or radius R, including helical moves), G17/G18/G19, G20/G21, G90/G91, G94/G95, G4, the mill drilling cycles G73, G81, G82 and G83 with G98/G99 and G80, plus F, S and M2/M30. Anything else is listed as not simulated rather than guessed at. It checks that each arc’s start and end radius agree to 0.002 mm.

The program you paste stays in this page. If you open it from one of our generators, it is passed in your browser’s session storage and removed once loaded.

FANUC, Haas, Siemens, Heidenhain, LinuxCNC and Grbl are names or trademarks of their respective owners. They are mentioned only to describe which controls a code format relates to. Lathe Calculator is not affiliated with or endorsed by any of them. Trademarks.

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