Wire Gauge Converter

Free online electrical unit converter.

Convert between all electrical units instantly with accurate results, formulas, and reference tables.

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Last updatedHow we build & check our tools

How This Tool Works

Our Wire Gauge Converter provides instant, accurate conversions across all major electrical units and wire gauges. Instead of relying on complex manual formulas, the tool utilizes a comprehensive database of established international standards (like AWG and mm²). When you input a value—for example, converting from 12 AWG to its equivalent cross-sectional area in cubic millimeters—the system calculates the precise ratio based on accepted electrical engineering constants.

It doesn't just give a number; it provides context. You can see conversions between units of resistance (Ohms), voltage, current (Amps), and gauge sizes. This ensures that whether you are working on residential wiring or industrial circuits, the relationship between your input unit and desired output unit is mathematically sound.

  • AWG to mm²: Converts American Wire Gauge standards.
  • Metric Conversions: Supports standard European/international metric sizing.

Why This Matters for Electrical Safety

Selecting the correct wire gauge is perhaps the most critical step in any electrical installation, directly impacting safety and efficiency. Using a wire that is too small (under-gauging) for the expected load causes excessive resistance, leading to overheating, insulation damage, and potentially fire—a major hazard.

Conversely, using an unnecessarily large gauge can lead to voltage drop over long distances. Our converter helps you calculate the minimum required gauge based on your total expected current draw (Amps) and distance. For instance, if a circuit needs to handle 25 Amps for 10 meters, the tool ensures you select wire that maintains optimal conductivity, protecting both your equipment and your home.

  • Safety First: Always verify gauge capacity against circuit breaker ratings.
  • Prevent Overheating: Proper sizing prevents resistive heat buildup.

Common Mistakes to Avoid

The biggest mistake electrical workers make is assuming that a wire size appropriate for one type of conductor (e.g., NM cable) will work for another (e.g., bare copper feeder). Electrical codes are specific, and conversion tools must be used with the correct context in mind.

Another common error is mixing unit systems—for example, calculating based on AWG but then applying a metric breaker rating. Always confirm that the gauge you select meets the minimum requirements for both the current (Amps) and the intended voltage. Never rely solely on visual inspection; always verify with a professional calculation.

  • Unit Confusion: Double-check if you are converting Amps to Ohms or vice versa.
  • Ignoring Load Type: Account for continuous loads (which require 125% of the normal load capacity).

Tips for Best Results

To maximize the accuracy and utility of this converter, always know your intended application before entering values. Are you calculating a feeder circuit, or just running an extension cord? The answer changes the required minimum gauge significantly.

When performing complex conversions involving voltage drop calculations (especially over long distances), remember that resistance increases exponentially with distance and inversely with conductor size. Use this tool to check your initial ratios, but always consult local electrical codes for final approval.

  • Factor in Distance: For feeders over 30 meters, voltage drop becomes critical.
  • Verify Material Type: Ensure the conversion accounts for copper vs. aluminum conductors.

Frequently Asked Questions

Common questions about the Wire Gauge Converter

AWG (American), SWG (British), metric (mm²). AWG is most common in North America.

Sources & References

International System of Units (SI): electric current, voltage and resistance

Electric current, voltage and resistance is measured in the ampere (A), volt (V) and ohm (Ω). Conversions between SI and other units use exact, internationally agreed factors maintained by NIST.

International System of Units (SI)

Authoritative definitions for electric current, voltage and resistance, from the BIPM SI Brochure (9th edition), the defining reference for the SI.