Voltage Drop Calculator for Electrician Study

Voltage-drop questions combine circuit theory, conductor data, distance, current, and installation judgment. Our voltage drop calculator is built for study: enter the known values, compare the result with your manual calculation, and review the substituted formula step by step.

A voltage-drop result by itself does not approve a conductor size. Conductor resistance, reactance, ampacity, temperature, termination limitations, and Code-specific design requirements are separate checks.

• Single-phase study model: Vdrop = 2 × I × R × L.
• Balanced three-phase study model: Vdrop = √3 × I × R × L.
• Practise voltage-drop percentage and the effect of distance, current, and conductor resistance.
• Check the result against a 3% branch-or-feeder or 5% total limit and see the voltage left at the load.
• Common mistakes include mixing metres and kilometres or confusing voltage drop with ampacity.