TIG on mild steel is about 1 amp per 0.001 inch. 1/8" starts near 125 A. At 1/8" of aluminum the calculator uses Miller’s 6061 butt start, 90–120 A, not a 1.5× factor. Other aluminum thicknesses use a published Lincoln row, or the nearest published row. None of this replaces scrap.
Stick: rod diameter ≈ half the base-metal thickness, then use the amperage window for that rod. MIG: 0.023" under 3/32", 0.030" through 3/16", 0.035" above. Duty cycle scales with the square of the amperage ratio — that's why turning the machine up cooks it faster than you think.
| Steel thickness | TIG amps | Stick rod | Machine class |
|---|---|---|---|
| 1/16" (62 mils) | 50–75 | 1/16" E6011 @ 35–60 | 120 V hobby |
| 1/8" (125 mils) | 100–150 | 1/8" E6011 @ 75–125 | 120 V ok, 240 V comfortable |
| 3/16" (188 mils) | 150–225 | 5/32" E6011 @ 110–165 | 240 V |
| 1/4" (250 mils) | 200–300 | 1/8" @ 90–140, multi-pass | 240 V, 180–220 A |
| 3/8"+ (375+) | 300+ | Multi-pass, preheat | Shop machine |
Amp windows from published Lincoln / Miller / ESAB charts, same as welding-calculator.com. Rod-diameter rule: never smaller than 1/16".
1/4" steel is the line between a 140 A hobby MIG and a real shop machine. If that's your job, don't buy the 120 V unit because the box said 'welds 1/4 inch' in tiny asterisks.
Solid-wire MIG starting points on this site follow the Miller page below: 1 amp per .001 inch of steel, and the wire-speed multipliers.
Yes — free to use, no signup, no email required.
Estimates follow industry-standard sizing rules and common safety margins. Always confirm with a licensed professional for final sizing.
Yes — the page is fully responsive and works on phones, tablets, and desktop.
Formulas are shown inline on the result panel so you can verify each step yourself.