Cable Sizing Calculator
Estimate a suitable cable cross-sectional area using load current, circuit length, conductor material, supply type, and maximum permitted voltage drop.
Enter circuit details
Result
Enter your circuit details to estimate the required cable size.
Voltage drop check
The calculator estimates conductor area from the allowed voltage drop and then rounds up to the next common cable size.
Current capacity check
A simplified design-current check is also applied so the selected cable is not based on voltage drop alone.
Installation matters
Cables in conduit, insulation, hot spaces, or grouped together may require a larger size than the estimate shown.
Frequently asked questions
What does cable size mean?
It is the conductor cross-sectional area, normally expressed in square millimetres (mm²). A larger area generally carries more current with less resistance and voltage drop.
Why is one-way length requested?
The formula automatically accounts for the return path in single-phase and DC circuits. Enter only the source-to-load distance.
What voltage-drop limit should I use?
Common design targets are around 3% for sensitive or lighting circuits and up to 5% for some general circuits, but local codes and project requirements take priority.
Can I use this result for final installation?
No. Final cable selection should be verified against the applicable electrical standard and installation conditions by a qualified professional.
Results are estimates generated locally in your browser using standard electrical formulas. They are for informational and planning purposes only, not a substitute for a qualified electrician. Confirm all wiring, load and safety requirements against your local electrical code before installation. VisionVix accepts no liability for decisions based on this tool's output.
