MIG starting calculator

Mild steel ballpark for ER70S-6 with C25 (75/25). Uses the common 1 A per 0.001" rule and wire-speed multipliers — then you tune on scrap.

Not a WPS. Practice starting points only — not code-qualified and not a substitute for your machine chart or wire manufacturer data. Scrap-test before any real part.

Inputs

Machine notes

Miller / Hobart-style door charts

Often land close to this calculator. If the arc stubs, bump voltage first; if it’s wild and spattery, drop a hair of voltage or ease WFS.

Lincoln / syncergic machines

Programs can run a different voltage for the same WFS. Treat these numbers as a scrap starting zone, then save what your machine likes.

Small 120V units

You may hit the machine’s ceiling before the “book” amps on thicker plate. That means multi-pass or step up the power source — not forcing the chart.

How this is calculated

Check the bead photo TIG calculator

Joint, position, stickout, and brand all move the window. Door chart wins when it disagrees.