Pick your process, material, thickness, and position — get your amperage range, wire or rod size, voltage and wire feed speed, shielding gas, polarity, and the machine class that actually handles the job. Starting points from standard charts, minus the chart-squinting.
Welding Amperage Calculator
Settings are starting points from standard amperage charts — always dial in on scrap first and check your machine and consumable manufacturer charts. Amperage assumes single-pass butt joints on clean material; dirty, painted, or galvanized steel changes everything (and galvanized fumes are toxic — grind the coating off).
The backbone is the classic rule: one amp per thousandth of an inch of mild steel. On top of that baseline we adjust for material — stainless runs about 10% cooler, aluminum about 25% hotter because it wicks heat away from the joint — and knock 10% off for vertical-up and overhead work where a cooler puddle is controllable. Wire, rod, and tungsten sizes follow standard consumable charts, wire feed speed comes from per-diameter multipliers, and the machine class adds real-world headroom, because a welder screaming at 100% output has the duty cycle of a mayfly.
Every machine, wire batch, joint fit-up, and slab of steel is a little different. Treat these numbers as where you set the dials before striking your first arc on scrap — then tune by sound and puddle. Gas-shielded MIG on clean steel should sizzle like bacon; popping means more voltage or less wire, hissing means the opposite. And the settings assume clean, bare metal: mill scale, paint, and especially galvanized coating change everything (grind galvanized off — the fumes are genuinely toxic).
Head to The Arc for machine reviews and technique guides, or jump into the gear that matches your process: MIG, TIG, stick, or plasma. And whatever you run, start with proper PPE — every setting on this page assumes you can still see.