Extension Cord Size Calculator
Find the right extension cord gauge (AWG) for your device based on amperage draw and cord length.
Recommended Cord
Extension cord gauge must match the amperage of your device and the distance the cord runs. Using too thin a cord causes voltage drop, overheating, and fire risk.
Wire gauge ratings (typical max amps):
| AWG | 25 ft | 50 ft | 100 ft | 150 ft |
|---|---|---|---|---|
| 16 | 13A | 10A | 7A | 5A |
| 14 | 15A | 13A | 10A | 7A |
| 12 | 20A | 15A | 13A | 10A |
| 10 | 25A | 20A | 15A | 13A |
Lower AWG = thicker wire = more capacity
Common device amperage:
- Phone charger: 0.5A
- Lamp: 0.5-1A
- Power drill: 3-6A
- Circular saw: 12-15A
- Space heater: 12.5A
- Window AC: 7-12A
Safety rules:
- Never daisy-chain extension cords
- Never run cords under rugs or through walls
- Use outdoor-rated cords outside (marked “W”)