Amp to Wire Size Calculator

Enter current, length, voltage, and allowable drop to size conductors.

How to Use This Calculator

Enter the expected current (amps), one-way cable run, supply voltage, allowable drop %, and material. The tool returns the minimum cross-sectional area to keep voltage drop within target.

Formula

A ≥ ρ · 2L · I / Vdrop,allow

Frequently Asked Questions

Does this include ampacity?

No. This converts amps to a wire size based on voltage drop only. Verify ampacity using code tables.