Per the National Electrical Code Article NEMA 392-9(b) cable tray fill calculations will be computed as follows. Cable Trays may be filled 50% when using control or signal wiring. The sum of the cross sectional areas of all cables cannot exceed 50% of the trays fill area. The cable tray equals the width times the loading depth. Generally, the tray will appear full of cables when it contains a 50% fill of cables.

Wire Basket Cable Tray Fill Calculator

Tray Size
# of 0.1852”
O.D. Cables
# of 0.21”
O.D. Cables
2” x 2”
74
57
2” x 4”
148
115
2” x 6“
222
173
2” x 6“
296
230
2" x 8"
296
230
2" x 12"
445
346
2" x 16"
593
461
2" x 18"
668
519
2" x 22"
816
635
2" x 24"
890
692
2" x 28"
1039
808
 
4" x 4"
296
230
4" x 8"
594
461
4" x 12"
890
692
4" x 14"
1039
808
4" x 16"
1187
923
4" x 18"
1336
1039
4" x 20"
1484
1154
4" x 24"
1781
1385
 
6" x 8"
890
692
6" x 16"
1781
1385
6" x 20
2227
1732