- No data uploaded
- Instant results
Wire Size for 90 Amps
A 90-amp load at 240 V over a 100 ft run needs 3 AWG copper (100 A rating · 4.41 V drop (1.8%)). Change the distance or voltage to re-size.
Wire Size for 90 Amps
Minimum wire size100 A rating · 4.41 V drop (1.8%)
| Size | Ampacity | Voltage drop |
|---|---|---|
| 14 AWG | 20 A | 55.26 V (23%) |
| 12 AWG | 25 A | 34.74 V (14.5%) |
| 10 AWG | 35 A | 21.78 V (9.1%) |
| 8 AWG | 50 A | 13.75 V (5.7%) |
| 6 AWG | 65 A | 8.84 V (3.7%) |
| 4 AWG | 85 A | 5.54 V (2.3%) |
| 3 AWG | 100 A | 4.41 V (1.8%) |
| 2 AWG | 115 A | 3.49 V (1.5%) |
| 1 AWG | 130 A | 2.77 V (1.2%) |
| 1/0 AWG | 150 A | 2.2 V (0.9%) |
| 2/0 AWG | 175 A | 1.74 V (0.7%) |
| 3/0 AWG | 200 A | 1.38 V (0.6%) |
| 4/0 AWG | 230 A | 1.09 V (0.5%) |
| 250 kcmil | 255 A | 0.93 V (0.4%) |
| 300 kcmil | 285 A | 0.77 V (0.3%) |
| 350 kcmil | 310 A | 0.66 V (0.3%) |
| 500 kcmil | 380 A | 0.46 V (0.2%) |
NEC Table 310.16 (75 °C column), 240.4(D) small-conductor limits and Chapter 9 Table 8 resistance. Apply continuous-load (125%), ambient temperature and bundling corrections, and follow your local code and AHJ.
Planning estimates only. Building codes, loads and material specs vary — have a licensed engineer or contractor confirm quantities and safety requirements. Disclaimer
Frequently asked questions
Is my data uploaded?
No. The calculation runs entirely in your browser — nothing you type is sent to a server.
Is it free?
Yes — free, unlimited and no sign-up.