Cable Voltage Drop Calculator

Calculate voltage drop in electrical cables for DC, single-phase AC, and three-phase AC circuits. Analyze power losses and determine proper wire sizing for electrical installations.

Cable Voltage Drop Analysis

Supply Voltage
Vsupply
Rcable
Vdrop
Length
Load Voltage
Vload
DC/Single Phase: Vdrop = 2 × I × R × L
Three Phase: Vdrop = √3 × I × R × L
% Drop = (Vdrop / Vsupply) × 100

Circuit Type

Circuit Parameters

V
A
ft

Cable Specifications

°C

About Cable Voltage Drop

Voltage drop in electrical cables reduces the voltage available at the load, affecting equipment performance and efficiency. Proper cable sizing minimizes voltage drop and power losses.

Key Factors:

  • Current: Higher current increases voltage drop
  • Length: Longer cables have higher resistance
  • Wire Size: Larger wires have lower resistance
  • Material: Copper has lower resistance than aluminum

Effects of Excessive Voltage Drop:

  • Reduced equipment performance and efficiency
  • Increased power consumption and costs
  • Potential equipment damage or malfunction
  • Violation of electrical codes and standards

Design Recommendations:

  • Keep voltage drop ≤3% for branch circuits
  • Use larger wire sizes for long runs
  • Consider higher voltage systems for long distances
  • Account for temperature effects on resistance