Cable Size Calculator
Estimate suitable cable size from electrical load and installation details.
V
Use 1.00 for resistive/DC loads.
This calculator uses voltage drop as a sizing check.
Cable sizing estimate
The calculator estimates current, voltage drop and a suitable standard cable cross-sectional area. Final cable selection should be checked against applicable electrical standards and actual installation conditions.
Cable Size Calculation
Cable sizing depends on load current, conductor resistance, cable length, installation conditions and allowable voltage drop. For AC loads, power factor also affects the estimated current.
Current estimate
Single-phase: current ≈ power ÷ (voltage × power factor)
Three-phase: current ≈ power ÷ (√3 × voltage × power factor)
DC: current ≈ power ÷ voltage
How to Use the Cable Size Calculator
Enter the Electrical Load
Enter voltage, load and power factor where applicable.
Enter Installation Details
Provide cable length, conductor material and installation method.
Set Voltage Drop
Choose the maximum voltage-drop percentage you want to allow.
Review the Estimate
Review calculated current, recommended cross-sectional area and estimated voltage drop.
Example
A 3,000 W single-phase load at 230 V with a 0.90 power factor.
Estimated current = 3,000 ÷ (230 × 0.90) ≈ 14.49 A.
The required cable size also depends on length, installation method and allowable voltage drop.