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Calculator

Cable Size Calculator

Calculate the correct cable cross-section for any run in your solar system based on current, voltage, and acceptable voltage drop.

Continuously maintained3 min read Focus Solar Editorial Team Reviewed for technical accuracy through the Focus Solar editorial process

Enter the current, cable length, system voltage, and maximum acceptable voltage drop to get the recommended minimum cable cross-section. The calculator covers both DC and AC runs and highlights configurations that exceed safe current ratings.

YOUR INPUTS

Estimate cable size

Adjust the assumptions. Results update immediately.
A
Range 1–500
m
Range 1–500
V
Range 12–1500
%
Range 0.5–10
Planning estimate only

How to use this estimate

This result is an early decision aid, not an approved electrical or structural design. Weather, shading, orientation, equipment efficiency, local rules, and actual product specifications can change the outcome.

Regional differences: Costs, taxes, incentives, tariffs, and grid rules vary by location and over time.

Read the calculation methodology →