metal Box
4" Square x 2-1/8" Deep
Deep 4-inch square electrical box ideal for multiple conductors and complex wiring configurations.
Quick answer
A 4" Square x 2-1/8" Deep (30.3 cu.in.) holds 13 × 12 AWG or 15 × 14 AWG conductors in a bare box under NEC 314.16.
Subtract two allowances for each device or strap, and one for each set of internal clamps, grounding conductors, or support fittings. Run your exact box fill →
30.3
cu.in. Volume
15
Max 14 AWG
13
Max 12 AWG
4" x 4" x 2-1/8"
Dimensions
Conductor Capacity per NEC 314.16
Maximum number of conductors that can fit in this box based on wire gauge (not accounting for devices, clamps, or grounds).
| Wire Gauge | Volume Each | Max Conductors* |
|---|---|---|
| 18 AWG | 1.5 cu.in. | 20 |
| 16 AWG | 1.75 cu.in. | 17 |
| 14 AWG | 2 cu.in. | 15 |
| 12 AWG | 2.25 cu.in. | 13 |
| 10 AWG | 2.5 cu.in. | 12 |
| 8 AWG | 3 cu.in. | 10 |
| 6 AWG | 5 cu.in. | 6 |
*Theoretical maximum for conductors only. Actual capacity will be less when including devices, clamps, and grounding conductors.
Common Applications
High-capacity junction
Multiple circuit connections
Commercial installations
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Use our free calculator to verify NEC 314.16 requirements.
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