Voltage drop calculation tool
Calculates conductor voltage drop based on Ohm's law, supports single-phase and three-phase circuits
Input Parameters
Note: The distance entered here is a one-way distance, and the round trip needs to be multiplied by 2
Calculation formula
Single phase circuit: VD = 2 × I × L × ρ / A
Three-phase circuit: VD = √3 × I × L × ρ / A
Where: VD=voltage drop (V), I=current (A), L=length (m), ρ=resistivity, A=cross-sectional area (mm²)
Voltage drop reference standard
High quality (≤2%)
Good (2%-3%)
Warning (3%-5%)
Dangerous (>5%)
According to GB/T 12345-2008, voltage drop should generally not exceed 5% of the rated voltage.
Copper core wire carrying capacity reference
1 mm²
6A
1.5 mm²
10A
2.5 mm²
16A
4 mm²
25A
6 mm²
32A
10 mm²
50A
* Ampacity is a reference value when the ambient temperature is 30°C