Cable Size Calculator

Load Current (Amps) Voltage (V) Cable Length (meters) Allowable Voltage Drop (%) Material Copper Aluminum

Result will appear here

Cable Size Calculator – Accurate Wire Size Selection Tool

The Cable Size Calculator helps you determine the correct electrical cable size based on load current, voltage, cable length, and allowable voltage drop. Choosing the right cable size is critical in electrical engineering to ensure safety, efficiency, and long-term reliability of electrical systems.

Undersized cables can lead to overheating, energy loss, and even fire hazards, while oversized cables increase installation cost unnecessarily. This calculator provides a balanced and practical solution for engineers, electricians, and students.

How Cable Size is Calculated

Cable size is mainly determined using voltage drop and current carrying capacity. The basic formula used is:

Cable Size (mm²) = (2 × Length × Current) / (Conductivity × Voltage Drop)

Where conductivity depends on material:

• Copper ≈ 56
• Aluminum ≈ 35

How to Use This Calculator

Enter the load current, system voltage, cable length, and permissible voltage drop percentage. Select the conductor material (copper or aluminum), then click the calculate button to get the required cable size instantly.

Example

Load Current = 20A, Voltage = 230V, Length = 30m, Voltage Drop = 3%

Result: Approx. 2.5 mm² copper cable

Applications in Electrical Engineering

Cable sizing is widely used in residential wiring, industrial installations, solar power systems, and power distribution networks. Proper cable selection ensures minimal power loss and protects equipment from voltage fluctuations.

In solar systems, correct cable size improves efficiency by reducing losses between panels and inverter. In industrial systems, it prevents overheating in motors and heavy machinery.

Importance of Correct Cable Selection

Using the right cable size improves system efficiency, reduces electricity losses, and enhances safety. It also ensures compliance with electrical standards and regulations.

This tool is especially useful for students preparing for exams like GATE, EEE, electrical diploma courses, and competitive exams. It also helps professionals quickly verify calculations during project design.