WireWicket / Field calculation / Ampacity
Ampacity derating calculator
Review the ambient-temperature and current-carrying conductor factors applied to a 30°C / 86°F base ampacity.
Calculation inputs
Ampacity basis
Use the 90°C conductor-temperature column from NEC Table 310.16. The base ampacity must be the corresponding value on the 30°C / 86°F basis.
Enter a positive ampacity in amperes.
No interpolation. Unverified NEC 2026 temperature rows show as unavailable.
Count conductors already classified as current-carrying under the NEC.
This tool does not determine neutral counting, installation exceptions, terminal temperature limits, or other conductor-specific limits.
Ampacity result
Awaiting valid inputs
Enter a base ampacity, whole-degree ambient temperature, and conductor count to see the factor breakdown.