Home › Wire size by amps › 100 amp
What size wire for 100 amps?
Advertisement
3 AWG copper
minimum for 100 A (75 °C column, NEC 310.16) · 1 AWG aluminum · typical for subpanels and small homes
100 amp wire size by distance (3% voltage drop, copper)
| One-way distance | 120 V | 240 V |
|---|---|---|
| 25 ft | 3 AWG | 3 AWG |
| 50 ft | 3 AWG | 3 AWG |
| 75 ft | 2 AWG | 3 AWG |
| 100 ft | 1 AWG | 3 AWG |
| 125 ft | 1/0 AWG | 3 AWG |
| 150 ft | 2/0 AWG | 2 AWG |
| 200 ft | 3/0 AWG | 1 AWG |
| 250 ft | 4/0 AWG | 1/0 AWG |
| 300 ft | 250 kcmil | 2/0 AWG |
Load assumed at the full 100 A. For continuous loads the circuit must be sized at 125% of the load (e.g. a 80 A continuous load on a 100 A breaker).
Check your exact run
FAQ
What size wire for a 100 amp circuit?
3 AWG copper or 1 AWG aluminum at 75 °C for short runs; longer runs need larger wire to limit voltage drop.
Can I use 3 AWG on a 100 amp breaker for 150 feet?
Check voltage drop: see the distance table on this page.
Other circuit sizes
- 15 amp wire size
- 20 amp wire size
- 25 amp wire size
- 30 amp wire size
- 35 amp wire size
- 40 amp wire size
- 45 amp wire size
- 50 amp wire size
- 60 amp wire size
- 70 amp wire size
- 80 amp wire size
- 90 amp wire size
- 110 amp wire size
- 125 amp wire size
- 150 amp wire size
- 175 amp wire size
- 200 amp wire size
- 225 amp wire size
- 250 amp wire size
- 300 amp wire size
- 350 amp wire size
- 400 amp wire size
Advertisement
Free calculator by WireMath