AWG Wire Size Chart
Interactive reference table for AWG wire gauges — diameter, resistance, and NEC ampacity ratings for copper conductors.
How to Read This Table
AWG (American Wire Gauge) is an inverse scale — smaller numbers mean larger wire. AWG 4/0 (0000) is the largest gauge in common use; AWG 40 is hair-thin. Each 3-step decrease in AWG roughly doubles the cross-sectional area and halves the resistance.
The three ampacity columns correspond to NEC Table 310.16 temperature ratings for conductor insulation: 60°C (older wiring, some fixtures), 75°C (most modern wiring, THWN), and 90°C (THHN, used for derating calculations). Always use the temperature rating appropriate for your insulation type and termination ratings.
Aluminum conductors carry roughly 61% of the current of equivalent-gauge copper, so aluminum must be upsized. For example, where 2 AWG copper carries 95A at 75°C, you would need 1/0 AWG aluminum for the same load.
Disclaimer: Ampacity values are from NEC Table 310.16 for not more than 3 current-carrying conductors in conduit at 30°C ambient. Always apply correction factors for higher ambient temperatures, more conductors, or specific installation conditions. Consult a licensed electrician and the current NEC edition for all wiring decisions.