With this calculator, you can calculate and size the necessary cable for your DC system. You can choose to input either the system's maximum power (P) or the voltage and current as the initial value. You can experiment with different wire sizes to see their effect on power and voltage losses. Ideally, aim for no more than a 5-10% power loss. Enter the total length of the cable as the combined length of both the positive and negative cables.
Below the calculator, you will also find an AWG to mm² conversion table, where you can see the mm² size corresponding to each AWG wire size. If needed, you can also use our Ohm's Law calculator.
The significance of conductor sizing in solar panels
The correct sizing of conductors is also important in solar power systems. Undersized cables between the panels and the charge controller create more resistance and lead to higher power losses. Choosing the wrong conductors can thus easily degrade the efficiency of solar panels.
AWG to mm² wire size conversion table
The table below can be used to find the mm² wire size corresponding to an AWG wire size.
| AWG # | Cable cross section mm² | AWG # | Cable cross section mm² |
|---|---|---|---|
| 0000 (4/0) | 120 | 16 | 1.5 |
| 000 (3/0) | 95 | 17 | 1 |
| 00 (2/0) | 70 | 18 | 0.75 |
| 0 (1/0) | 50 | 20 | 0.5 |
| 2 | 35 | 21 | 0.38 |
| 4 | 25 | 22 | 0.34 |
| 6 | 16 | 24 | 0.25 |
| 8 | 10 | 26 | 0.14 |
| 10 | 6 | 28 | 0.08 |
| 12 | 4 | 30 | 0.05 |
| 14 | 2.5 |
More about resistance on Wikipedia.