NEC Derating Calculator

NEC 310.15

Apply NEC temperature correction and conductor bundling adjustment factors to find derated ampacity.

Conductor

Wire Gauge

Insulation Type

Conductor Material

CopperAluminum

Conditions

Ambient Temperature

°C

Current-Carrying Conductors

Results

Base Ampacity

40A

Temp Correction Factor

1.00

Bundling Factor

1.00

Derated Ampacity

40.0A

Ampacity Waterfall

Base Ampacity40.0 A

40.0 A

After Temp Correction40.0 A

40.0 A

After Bundling Adj.40.0 A

40.0 A

Derating Steps

1Base Ampacity

10 AWG at rated temperature

40.0 A

2Temp Correction

Ambient temperature factor

× 1.00

40.0 A

3Bundling Adj.

Conductor fill factor

× 1.00

40.0 A

Conductor

Wire Gauge

Insulation Type

Conductor Material

CopperAluminum

Conditions

Ambient Temperature

°C

Current-Carrying Conductors

Results

Base Ampacity

40A

Temp Correction Factor

1.00

Bundling Factor

1.00

Derated Ampacity

40.0A

Ampacity Waterfall

Base Ampacity40.0 A

40.0 A

After Temp Correction40.0 A

40.0 A

After Bundling Adj.40.0 A

40.0 A

Derating Steps

1Base Ampacity

10 AWG at rated temperature

40.0 A

2Temp Correction

Ambient temperature factor

× 1.00

40.0 A

3Bundling Adj.

Conductor fill factor

× 1.00

40.0 A