Table 310.16 · 310.12 · 250.122

Wire size, by breaker, service and sub panel

Verified against NEC 2023, checked against the 2026 edition · Last checked August 18, 2026

Pick a rating and get the minimum copper and aluminum conductor, the ground size and the exact NEC basis. Every number is computed from the same verified dataset that powers the JobVolt app, never typed by hand.

By breaker rating

Every standard 240.6(A) rating from 15 A to 1200 A, copper and aluminum.

15 A
20 A
25 A
30 A
35 A
40 A
45 A
50 A
60 A
70 A
80 A
90 A
100 A
110 A
125 A
150 A
175 A
200 A
225 A
250 A
300 A
350 A
400 A
450 A
500 A
600 A
700 A
800 A
1000 A
1200 A

By dwelling service

One-family services 100 A to 400 A under the 83% rule of 310.12.

100 A
110 A
125 A
150 A
175 A
200 A
225 A
250 A
300 A
350 A
400 A

By sub panel

Feeder sizes for the common sub panel ratings, 30 A to 200 A.

30 A
40 A
50 A
60 A
70 A
100 A
125 A
150 A
200 A

Every chart here lives in the app, offline.

JobVolt sizes wire, conduit, boxes and motor circuits with the derivation and code section on every line, then exports inspector-ready PDF submittals.