48V Inverter Cable Size Calculator

How to use this calculator

1. Choose the system voltage (12, 24 or 48 V) and enter the load or inverter power in watts.
2. Enter the one-way cable length and the maximum voltage drop you accept (often 2–3%).
3. Click Size the cable for the current, the minimum cross-section and the closest standard size.

Why low-voltage DC needs thick cable

At low voltage the current is high for the same power, and even a small drop is a large percentage. The cross-section comes from the copper resistivity, the round-trip length and the allowed drop:

Because the current doubles when the voltage halves, a 48 V system needs far thinner cable than a 12 V system for the same power.

Current for 2000 W by system voltage

Keep battery-to-inverter runs as short as possible and terminations clean and tight — most low-voltage faults are loose, hot connections.

Frequently asked questions

What size cable for a 48V inverter?

Work out the current (power ÷ 48 V), then size the cross-section for your run length and a 2–3% drop. A 3000 W 48 V inverter draws about 63 A and typically needs 16 mm² (≈6 AWG) for a short run.

Why does a 12V system need such thick cable?

For the same power, 12 V draws four times the current of 48 V, and the allowed voltage drop in volts is tiny — so the cable must be much larger to keep losses down.

What voltage drop should I allow on DC?

Keep battery and inverter cables to about 2–3% drop. Lower is better on the main battery cables, where high current makes any resistance costly.