Voltage Drop & Wire Gauge Calculator
Required wire cross-section from length, current and drop.
Values
Result
A ≈ 0.58 mm²
Sizing wire for voltage drop
The round-trip wire resistance must stay low enough that the load still sees its voltage: Rmax = ΔV / I, and with resistivity and one-way length L, A = 2·ρ·L·I / ΔV.
Example: 12 V, 5 A, 10 m one-way, 3% drop (0.36 V) → copper needs ≈ 0.58 mm² (≈ AWG 20). Go one size up for margin.