Wire Gauge / Amperage Calculator

Wire Gauge & Amperage Calculator

Find the minimum copper wire gauge (AWG) for a given amperage, plus the typical breaker and common uses.

Based on the NEC 60°C/75°C copper ampacity guideline for typical residential branch circuits. This is reference information, NOT a substitute for the National Electrical Code or a licensed electrician. Long runs need an upsize for voltage drop — check our voltage drop calculator. Always follow local code.
Wiring a circuit? Shop wire & cable, outlets & switches, breakers and wire strippers.
More free tools:PaintTileLumensWire GaugeConcreteBoard FootFan SizeVoltage DropMERV FinderBulb BrightnessAll tools →

What wire gauge for how many amps?

Smaller AWG numbers mean thicker wire and higher capacity. For standard copper residential circuits: 14 AWG = 15 A, 12 AWG = 20 A, 10 AWG = 30 A, 8 AWG = 40 A, 6 AWG = 55 A. Aluminum carries less, so size up one step. For runs over ~100 ft, check voltage drop with our voltage drop calculator.

Copper AWG Amps Common breaker
14 15 15 A
12 20 20 A
10 30 30 A
8 40 40 A
6 55 50 A