Box Fill Calculator
Calculate required box volume per NEC 314.16(B). Enter your conductors, devices, clamps, and grounding conductors — WireCoder totals the volume allowance and tells you if the box is big enough.
How it works
Each conductor counts by its AWG volume allowance (Table 314.16(B)). A device yoke counts as two of the largest conductor, clamps as one, and all grounds together as one of the largest ground.
Frequently asked questions
How is a device counted?
Each strap/yoke counts as twice the volume allowance of the largest conductor connected to it.
How are grounds counted?
All equipment grounding conductors together count as a single volume allowance of the largest ground.