AWG Wire Gauge Calculator

Diameter in millimetres equals 0.127 x 92^((36 - AWG) / 39). It is a geometric series, so each six-gauge step roughly halves or doubles the diameter, and each three-gauge step changes the area by about half.

Thinner. AWG is an inverse scale, so AWG 24 is much thinner than AWG 12. Wires thicker than AWG 0 use 00, 000 and 0000, which this tool represents as -1, -2 and -3.

From R = rho x length / area, with length set to 1000 m and copper resistivity rho of 1.68e-8 ohm-metres. That simplifies to 16.8 divided by the area in square millimetres for a solid conductor.

From -3 up to 40, where -3 stands for 0000 (4/0) and higher numbers are thinner. Values outside that range are rejected because they fall outside the practical catalogue.

Yes. The formula is continuous, so a value like 12.5 returns a diameter between AWG 12 and 13, and negative numbers cover the 0, 00, 000 and 0000 sizes.

This calculator assumes a single solid copper conductor at 20 C. Stranded wire packs slightly less copper into the same nominal gauge, and higher temperatures raise resistance, so real values run a little above these.

No. It reports diameter, area and DC resistance, not ampacity. Safe current depends on insulation rating, bundling, ambient temperature and code tables, so always check the relevant wiring standard.

Area in square millimetres sets how much current the conductor can carry before overheating and drives the resistance. A larger area carries more current with less heating and less voltage drop.

No. The whole calculation happens locally in your browser. The AWG number you type is never sent to or stored on a server.