Long cable runs lose voltage, and lights flicker or motors struggle when the drop is too high. Enter the load, the route length and the conductor; the calculator lists every standard cross-section with its voltage drop in volts and per cent, and highlights the smallest one within your limit.
How to use it
- Choose single-phase 230 V or three-phase 400 V and enter the design current (or the power and power factor).
- Enter the one-way route length of the cable.
- Pick the allowed drop: typically 3 % for lighting and 5 % for other uses on a public supply.
- Then check the same cable for current-carrying capacity and fault disconnection — voltage drop is only one of the checks.
Step-by-step guides
- Cable Sizing for Voltage Drop: Formula, Limits and Worked Example
- MCB Selection and Discrimination: A Practical Design Guide
- TN-S vs TN-C-S vs TT Earthing: Systems Explained (Plus IT)
More free tools
Results are for preliminary design and checking. Always confirm against the standard edition and local regulations that apply to your project.
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