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Solar Panel Wire Sizing Calculator

Size PV array cable from string current, system voltage and run length. Applies the 125 percent continuous factor, checks voltage drop and ampacity, and returns AWG with power loss.

Array
Run
Results
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recommended size
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voltage drop
Notes

About Solar Panel Wire Sizing Calculator

The Solar Panel Wire Sizing Calculator sizes PV array conductors from string current, system voltage and run length. It applies the 125% continuous-duty factor and checks the result against both ampacity and a voltage-drop limit.

Features

  • Copper or aluminum conductors
  • 125% continuous-duty factor
  • Run length in feet or metres
  • Adjustable voltage-drop limit
  • Drop reported in volts and percent

How to Use

  1. Enter system voltage, string current and one-way run length.
  2. Pick the material and whether the 125% factor applies.
  3. Read the recommended size and the resulting drop.

Examples

Example: 15 A at 48 V over 50 ft of copper with the 125% factor -> 8 AWG, 18.8 A design current, and a 1.18 V one-way drop (2.45%).

Benefits

  • Low-voltage DC runs are drop-limited, and this shows it directly
  • The 125% factor is applied automatically rather than remembered

Frequently Asked Questions

What does this calculator do?
Size PV array cable from string current, system voltage and run length. Applies the 125 percent continuous factor, checks voltage drop and ampacity, and returns AWG with power loss.
Is my data stored?
No. Everything runs in your browser; nothing is uploaded, saved or logged.