Wire Ampacity Calculator
Calculate the maximum current carrying capacity (ampacity) for different wire gauges based on installation method and temperature ratings.
Calculate Wire Ampacity
Ampacity Results
Base Ampacity
25 A
Standard rating @ 75°C
Derating Factors
100%
Temp: 100% × Bundle: 100%
Adjusted Ampacity
25 A
After derating
Common Applications for 12 AWG copper
✓ General purpose outlets (20A breaker)
What is Wire Ampacity?
Ampacity is the maximum amount of electrical current a conductor can carry before sustaining damage. It's determined by wire size, insulation temperature rating, installation method, and ambient conditions. Proper ampacity selection ensures electrical safety and NEC code compliance.
Key Factors
- • Wire size (larger = higher ampacity)
- • Material (copper > aluminum)
- • Temperature rating (higher = more capacity)
- • Installation method (free air vs conduit)
- • Conductor bundling (reduces capacity)