Quick Reference — 1/0 (0 AWG)
Common uses: Service entrance cables, large feeder circuits, industrial power, battery cables
Wire Properties
| AWG Size | 1/0 (0 AWG) |
| Diameter (inches) | 0.3249″ |
| Diameter (mm) | 8.252 mm |
| Cross-sectional area | 53.5 mm² (105600 circular mils) |
| Resistance — Copper | 0.0983 Ω per 1000 ft @ 20°C |
| Resistance — Aluminum | 0.161 Ω per 1000 ft @ 20°C |
| Weight (copper) | ~319.7 lb per 1000 ft |
Ampacity (Current Carrying Capacity)
Per NEC Table 310.16 — Copper conductor, 3+ current-carrying conductors in raceway/cable:
| Insulation Rating | Ampacity |
|---|---|
| 60°C (TW, UF) | 125A |
| 75°C (THW, THWN, XHHW) | 150A |
| 90°C (THHN, XHHW-2) | 170A |
Note: Actual ampacity may be reduced by ambient temperature corrections and conduit fill derating factors per NEC 310.15.
Voltage Drop Example
For a 15A load on 1/0 (0 AWG) copper wire, 100 ft one-way run (120V circuit):
Wire resistance: 0.0983 Ω/1000ft × 200ft (round trip) ÷ 1000 = 0.0197 Ω
Voltage drop: 15A × 0.0197 Ω = 0.29V
Percent drop: 0.29V ÷ 120V = 0.2%
NEC recommends ≤3% voltage drop for branch circuits, ≤5% total (feeder + branch).
Nearby Sizes for Comparison
| AWG | Dia (in) | Dia (mm) | Area (mm²) | Ω/1000ft Cu | Ampacity 75°C |
|---|---|---|---|---|---|
| 3/0 | 0.4096 | 10.404 | 85.0 | 0.0618 | 200A |
| 2/0 | 0.3648 | 9.266 | 67.4 | 0.078 | 175A |
| 1/0 | 0.3249 | 8.252 | 53.5 | 0.0983 | 150A |
| 1 | 0.2893 | 7.348 | 42.4 | 0.124 | 130A |
| 2 | 0.2576 | 6.544 | 33.6 | 0.156 | 115A |
⚠️ AWG Sizing Reminder
- In AWG, lower numbers = thicker wire. 4 AWG is much thicker than 14 AWG.
- Each 3-gauge decrease doubles the cross-sectional area (e.g., 11 AWG ≈ 2× the area of 14 AWG).
- Each 6-gauge decrease doubles the diameter.
- Always follow local electrical codes — NEC values are minimum requirements.
Calculate voltage drop for your circuit
Stop looking it up twice — run the numbers and keep the record.
This reference is free forever. When you need to actually calculate, document, and defend the result, do it in the app — then export a clean report you can hand to a reviewer.
- ✓46 engineering calculators, unlimited
- ✓Save & reload every calculation
- ✓Organize work into project folders
- ✓Branded, PE-stamped PDF reports
Free plan, no credit card. Upgrade only when it's paying for itself.