Cable Size Calculator
Calculate the recommended cable size (cross-sectional area) for electrical installations based on current, voltage, length, and material.
Published by:
isCalculator Editorial Team
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How to use this tool?
How to Use the Cable Size Calculator
This calculator determines the minimum cross-sectional area (in mm²) of a cable needed for a given electrical load, based on voltage drop limits.
- Step 1: Enter the Current (Amps) the cable will carry.
- Step 2: Enter the Voltage (Volts) of the system.
- Step 3: Enter the Cable Length (meters) – use metric units only.
- Step 4: Select the Material (Copper or Aluminum).
- Step 5: Select the Phase (Single-Phase or Three-Phase).
- Step 6: Set the Max Voltage Drop (%) (default is 3%).
- Step 7: Click "Calculate Cable Size".
The result shows the recommended cable size in mm², along with the formula used. All inputs must be positive numbers.
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Frequently Asked Questions
It calculates the minimum cross-sectional area of a cable to ensure safe voltage drop and prevent overheating in electrical installations.
You need the current (amps), voltage (volts), cable length (meters), material (copper or aluminum), phase (single or three), and maximum allowed voltage drop percentage.
Using the correct cable size prevents voltage drop beyond acceptable limits, reduces energy loss, and avoids overheating which can cause fire hazards.
No, this calculator provides a basic estimate based on voltage drop. For detailed installations, consult electrical codes and consider derating factors.