Conduit Fill & Box Fill Calculators

Calculate raceway fill percentages per NEC Chapter 9 Tables and outlet box fill volumes per NEC 314.16. Supports EMT, RMC, PVC, and FMC raceways.

2 Calculators NEC Chapter 9 NEC 314.16

NEC Chapter 9

Determine if your conductors fit within a raceway based on NEC Chapter 9 fill percentages. Supports mixed conductor types and sizes.

Conduit Type

Conduit Trade Size

Conductors

NEC 314.16

Calculate outlet box fill per NEC 314.16(B). Accounts for conductors, devices, clamps, and equipment grounding conductors.

Box Type

Standard Box

Conductors (count each wire entering or leaving the box)

#14 AWG

#12 AWG

#10 AWG

#8 AWG

#6 AWG

Number of Devices (switches/receptacles)

Largest Conductor Connected to Device

Internal cable clamps present

Equipment grounding conductors present