Wire Gauge Calculator
Calculate the perfect wire size for your electrical project in seconds
How to Use This Calculator
- 1 Enter the current (in amps) that will flow through the wire
- 2 Select your system voltage (12V, 24V, 120V, etc.)
- 3 Enter the wire length (one-way distance, not round trip)
- 4 Set the maximum voltage drop you can tolerate (3% is standard)
- 5 The calculator will instantly show the recommended wire gauge
AWG Wire Gauge Chart
| AWG | Diameter (mm) | Resistance (Ω/km) | Max Current (A) |
|---|---|---|---|
| 18 | 1.02 | 21.0 | 10 |
| 16 | 1.29 | 13.2 | 13 |
| 14 | 1.63 | 8.3 | 17 |
| 12 | 2.05 | 5.2 | 23 |
| 10 | 2.59 | 3.3 | 33 |
| 8 | 3.26 | 2.1 | 46 |
| 6 | 4.11 | 1.3 | 60 |
| 4 | 5.19 | 0.82 | 80 |
| 2 | 6.54 | 0.51 | 115 |
| 1 | 7.35 | 0.41 | 130 |
| 1/0 | 8.25 | 0.32 | 150 |
| 2/0 | 9.27 | 0.26 | 175 |
Frequently Asked Questions
What is voltage drop?
Voltage drop is the reduction in voltage as electricity flows through a wire. Longer wires and higher currents cause more voltage drop. Keeping it under 3% ensures your devices receive adequate power.
Should I measure one-way or round-trip length?
Enter the one-way length. The calculator automatically accounts for the return path (round trip) in its calculations.
What if I need a wire size between two AWG gauges?
Always round up to the next larger (smaller number) gauge. For example, if calculations suggest between 12 AWG and 10 AWG, use 10 AWG for safety.
Can I use this for AC and DC circuits?
Yes! The calculator works for both AC and DC circuits. Just select the appropriate voltage from the dropdown.