Cable Size Calculator
Calculate the correct cable size based on load current, voltage drop, distance, phase, and conductor material.
📘 User Guide (Click to Open)
What Is a Cable Size Calculator?
A cable size calculator helps determine the correct wire size to safely carry electrical current without excessive voltage drop or overheating.
Why Cable Sizing Is Important
- Prevents voltage drop
- Avoids cable overheating
- Improves equipment performance
- Ensures electrical safety
How This Calculator Works
The calculation is based on:
- Ohm’s Law
- Voltage drop formula
- Material resistivity (Copper / Aluminum)
- Phase type (Single / Three phase)
Formula Used
Single Phase:
VD = (2 × I × L × R) / A
Three Phase:
VD = (√3 × I × L × R) / A
Recommended Voltage Drop
- 3% – Ideal for lighting & sensitive equipment
- 5% – Acceptable for general loads
Example
For a 20A single-phase load at 230V, 30 meters distance, copper conductor and 3% voltage drop, the recommended cable size is around 2.5–4 mm².