Wire Ampacity Chart
NEC ampacity table for copper conductors at 75°C. Look up maximum current-carrying capacity by AWG gauge.
How It Works
NEC ampacity table for copper conductors at 75°C. Look up maximum current-carrying capacity by AWG gauge. Enter your values above and click Calculate to get instant results.
Formula
Ampacity based on NEC 310.15, copper conductor, 75°C rating, not more than 3 current-carrying conductors
Quick Examples
- AWG 14 → 20A max (15A breaker typical)
- AWG 12 → 25A max (20A breaker typical)
- AWG 10 → 35A max (30A breaker typical)
Frequently Asked Questions
What temperature rating should I use?
Use the 75°C column for most residential and commercial wiring with standard breakers. 90°C ratings may be derated based on installation conditions.
What is ampacity?
Ampacity is the maximum current a wire can carry continuously without exceeding its temperature rating. It depends on wire size, insulation type, and installation conditions.