Voltage Drop Calculator Australia May 2026

| Cable Size (mm²) | Max run for 10A (230V) @ 5% | Max run for 20A (230V) @ 5% | | :--- | :--- | :--- | | | 35 meters | Not recommended | | 2.5mm² | 58 meters | 29 meters | | 4mm² | 93 meters | 46 meters | | 6mm² | 140 meters | 70 meters |

Next time a customer asks, "Why can't I just use 1.5mm² cable for my 200-meter driveway light?" send them here. voltage drop calculator australia

Example: A 20A circuit, 50 meters away, using 2.5mm² cable. (50 x 20 x 0.017) / 2.5 = 6.8 Volts lost. (6.8V / 230V = 2.9% drop – acceptable for general use). | Cable Size (mm²) | Max run for

In Australia, we deal with unique challenges. Our properties are massive (often measured in hectares, not square meters), and our standard 230V single-phase power has a long way to travel. Solar panels (DC) are far less forgiving than AC

Solar panels (DC) are far less forgiving than AC. Because voltage is lower (12V, 24V, or 48V), a 1V drop is a huge percentage. For DC systems (caravans, off-grid), aim for 3% max , not 5%.