🔌 Wire Gauge Calculator (AWG)

Convert American Wire Gauge to diameter, cross-section and a typical current rating — or work backwards from the amps you need.

About wire gauge (AWG)

American Wire Gauge (AWG) is a logarithmic scale: a smaller number means a thicker wire. Each 6-gauge step roughly doubles the diameter, and each 3-gauge step doubles the cross-sectional area. Diameter follows a fixed formula, so this tool computes mm and mm² exactly; the current rating (ampacity) shown is a common reference figure.

Safety: ampacity depends on insulation type, ambient temperature, bundling and length (voltage drop). These figures are a guide only — always follow your local electrical code (NEC, IEC) and the wire/insulation rating for real installations.

Picks the smallest gauge whose reference ampacity meets your current. Add margin for long runs (voltage drop) and high ambient temperature.

AWG to mm AWG to mm² amps to wire gauge wire size chart cable size