Cable Size Calculator for Voltage Drop & Ampacity
Determine proper cable cross-section based on load current and voltage drop limits.
Use this cable size calculator to determine recommended cable cross-section based on current load, voltage level, cable length, conductor material, and allowable voltage drop.
Circuit Details
Electrical System
V
Amps
Cable Run & Material
%
Recommended Cable
Standard Size
Min. Cross Section
25
mm²
Satisfies both VD and Ampacity
Max Capacity
101
A
Copper rating in air
Voltage Drop (VD)
Actual Performance
Voltage Drop Percentage
2.1
%
Within 3.0% limit
Absolute Drop
8.4
V
Total volts lost in run
Engineering Reference
3-Phase Voltage Drop
VD = (√3 × I × L × ρ) / A
1-Phase Voltage Drop
VD = (2 × I × L × ρ) / A
- L = Length in meters
- I = Load Current (A)
- ρ = Resistivity (Cu: 0.0175, Al: 0.028)
- A = Cable Area (mm²)