Box Fill Calculator
Decimals (in results):
AWG
Items Contained Within Box
#
18
16
14
12
10
8
6
Conductors that originate outside box
1
Conductors that pass through box without splice or connection (less than 12 in. in total length)
1
Conductors 12 in. or greater that are looped (or coiled) and unbroken (see 300.14 for exact measurement)
2
Support fittings (such as luminaire studs or hickeys)
1
Internal cable clamps (one or more)
1 only
Equipment grounding conductor (one or more)
1 only
Isolated equipment grounding conductor (one or more) [see 250.146(D)]
1 only
Conductors that originate within box and do not leave box
0
Fixture wires [per 314.16(B)(1), Exception]
0
Devices (such as receptacles, switches) or utilization equipment (such as timers, dimmers, AFCI receptacles, GFCI receptacles, TVSS receptacles)
2
Number of conductors
#
Free Space Within Box for Each Conductor
in
3
1.50
1.75
2.00
2.25
2.50
3.00
5.00
Free Space Within Box for Each Conductor
cm
3
24.6
28.7
32.8
36.9
41.0
49.2
81.9
Free Space Within Box for Each AWG
in
3
Free Space Within Box for Each AWG
cm
3
Free Space Within Box
in
3
Free Space Within Box
cm
3
Bibliografía
NEC 2017