🔌 Wire Gauge Calculator
Works for 12V, 24V & 48V systems
System Voltage
Or use watts below to calculate
Watts ÷ Volts = Amps
One-way distance from source to device
3% is best for sensitive electronics
Wire Type
OFC (pure copper) is always preferred. CCA (copper-clad aluminum) requires sizing up one gauge.
✅ Your Results
ALWAYS SIZE UP IN DOUBTMinimum Wire Gauge
4
AWG
Amperage
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System Voltage
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Run Length
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Voltage Drop
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Recommended Fuse
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Wire Type
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🔎 What This Means
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Quick Reference
AWG Wire Gauge Chart
The most amps each copper wire size can carry on a 12V system with no more than 3% voltage drop, for a 10-foot and a 20-foot run (one way). Same math as the calculator above. 8 AWG and thicker assume cable with 105°C-rated insulation (printed on the jacket). Longer run? The safe amps drop fast, so use the calculator.
| AWG | Max Amps (10 ft) | Max Amps (20 ft) | Common Uses |
|---|---|---|---|
| 18 AWG | 2.5A | 1.4A | Switch and relay trigger wires, LED strips |
| 16 AWG | 4A | 2A | Small LED lights, USB ports on short runs |
| 14 AWG | 7A | 3.5A | Fans, lights, short fridge runs |
| 12 AWG | 11A | 5.5A | Fridge, lighting runs, 12V sockets |
| 10 AWG | 18A | 9A | Fuse block feeds, solar controller output (short runs) |
| 8 AWG | 28A | 14A | DC-DC charger output, 30A solar controller (short runs) |
| 6 AWG | 45A | 22A | 40A DC-DC charger input, 300W inverters |
| 4 AWG | 72A | 36A | 500W inverters, long DC-DC charger runs |
| 2 AWG | 115A | 57A | 1000W inverters, Big 3 upgrade |
| 1/0 AWG | 180A | 91A | 1500W inverters, main battery cables |
| 2/0 AWG | 200A | 115A | 2000W inverters, high-output alternators |
| 4/0 AWG | 280A | 183A | Long inverter runs, main cables on big systems |