Why WireSize
Pick the right conductor: NEC 310.16 and IEC 60364-5-52 ampacities with ambient-temperature and grouping derating, continuous-load factor, breaker suggestion and a voltage-drop cross-check.
NEC & IEC tables
Copper/aluminum, 60/75/90°C; PVC/XLPE method C.
Derating built in
Ambient temperature and grouped-circuit factors.
Continuous load
125% design current with one switch.
Breaker suggestion
Standard sizes with small-conductor caps.
VD cross-check
Warns when the run is long for the size.
Glove-friendly
Field-first design, works offline.
How it works
Enter the load
Amps, continuous or not.
Set conditions
Ambient °C and how many circuits share the route.
Read the pick
Wire size, corrected ampacity, breaker.
FAQ
Which tables are used?
NEC Table 310.16 and IEC 60364-5-52 method C, with standard correction factors — test-verified against published values.
Does it handle 90°C wire?
Yes, all three NEC temperature columns.
IEC grouping?
Grouped circuits per B.52.17.
Who is it for?
Electricians and engineers sizing branch circuits and feeders.