AWG Current Capacity (Ampacity)

Pick a wire gauge and settings to estimate a practical current capacity. Includes a reference table and Show Work.

How to Use

  1. Select your AWG gauge.
  2. Choose material (copper or aluminum).
  3. Select an insulation temperature rating (typical 60/75/90°C).
  4. Pick a context (chassis wiring vs power transmission) if applicable.
  5. Review the estimated ampacity, notes, and the reference table.

This tool provides practical estimates. Final limits depend on standards, installation method, ambient temperature, bundling, and insulation type.

Inputs
Fast estimate based on embedded reference tables (client-side).
Tip: For automotive battery cables you’ll often see 4–1/0 AWG ranges.
Aluminum typically carries less current than copper at the same AWG.
Higher insulation ratings generally allow higher ampacity in common tables.
Context helps select a conservative vs typical estimate set.
Optional: used for simple derating guidance (tool JS decides if applied).
Optional: bundling can reduce ampacity due to heat.

Quick Reference

The table below is filled by the tool (client-side) based on your settings.

Selected Gauge
—
Material
—
Temp Rating
—
Context
—
AWG Ampacity Notes
Choose settings and click Calculate to populate the reference rows.

If you need standards-specific values (NEC/IEC/SAE, insulation type, install method), use the Reference/Details section below.

Show Work / Details
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Show Work explains which table was used and any derating guidance applied. (No URL updates unless you press Share.)

Reference Notes

  • Ampacity varies with insulation type, ambient temperature, bundling, and installation method.
  • Chassis wiring (shorter/open-air) is often less conservative than power transmission style tables.
  • Voltage drop is a separate constraint—wire can be “safe” thermally but unacceptable for drop.
  • Use appropriate fusing/protection for the circuit; wire size is only one part of safety.

Tool Info

Last updated:

Updates may include expanded gauge ranges, improved table clarity, and edge-case handling.