8
8 AWG Wire Box Fill
8 AWG conductors support 40-amp circuits for ranges and large appliances.
3
cu.in. per conductor
49.2
mm3 per conductor
40A
Max Ampacity
Common Applications
40-amp circuits
Electric ranges
Large AC units
Hot tubs
Box Capacity 8 AWG
Maximum number of conductors that fit in common electrical boxes (conductors only, not accounting for devices, clamps, or grounds).
| Box Type | Volume | Max 8 AWG* |
|---|---|---|
| 4" Square x 1-1/4" Deep | 18 cu.in. | 6 |
| 4" Square x 1-1/2" Deep | 21 cu.in. | 7 |
| 4" Square x 2-1/8" Deep | 30.3 cu.in. | 10 |
| 4-11/16" Square x 1-1/4" Deep | 25.5 cu.in. | 8 |
| 4-11/16" Square x 1-1/2" Deep | 29.5 cu.in. | 9 |
| 4-11/16" Square x 2-1/8" Deep | 42 cu.in. | 14 |
| Octagon Box 1-1/2" Deep | 15.5 cu.in. | 5 |
| 4" Octagon Box 1-1/2" Deep | 15.5 cu.in. | 5 |
| Octagon Box 2-1/8" Deep | 21.5 cu.in. | 7 |
| Single Gang Device Box 2-3/4" Deep | 14 cu.in. | 4 |
| Single Gang Device Box 18 cu.in. | 18 cu.in. | 6 |
| Single Gang Device Box 3-1/2" Deep | 18 cu.in. | 6 |