MM² to AWG Converter

How to Convert mm² to AWG

Converting square millimeters (mm²) to American Wire Gauge (AWG) is essential for anyone working with international wiring standards. While mm² is commonly used in Europe and most of the world, AWG is the standard in North America. Understanding this conversion ensures proper sizing, compatibility, and safety in electrical systems.

Square millimeters represent the actual cross-sectional area of a wire, while AWG is a logarithmic scale based on wire diameter. Because these systems differ in structure, conversion often requires reference tables or precise calculations.

What Is mm²?

Millimeters squared (mm²) is a metric unit used to measure the cross-sectional area of a wire. It is widely adopted globally for defining wire size and is directly related to a wire’s ability to carry current. The higher the mm², the thicker and more conductive the wire.

What Is AWG?

AWG (American Wire Gauge) is a standardized wire sizing system used primarily in North America. It assigns a number to wires based on their diameter—the higher the number, the thinner the wire. For example, a 14 AWG wire is thinner than a 10 AWG wire.

Conversion Formula

There is no direct linear formula to convert mm² to AWG, as AWG is logarithmic. However, the approximate conversion formula is:

AWG ≈ -39 × log₁₀(mm² / 0.0005067) + 36

This formula gives a close estimate, but because rounding and tolerances vary, it's recommended to use a conversion table for practical use.

Examples

• Example 1: To convert 1.5 mm² to AWG:
  1.5 mm² ≈ 15 AWG

• Example 2: To convert 2.5 mm² to AWG:
  2.5 mm² ≈ 13 AWG

• Example 3: To convert 10 mm² to AWG:
  10 mm² ≈ 8 AWG

These values are approximate and should always be verified against an official chart when accuracy is critical.

Conversion Table

This table offers a quick reference for matching mm² sizes to their closest AWG equivalents.

Practical Applications

• Importing Electrical Equipment: Professionals need to convert mm² to AWG when installing imported components or integrating global products.

• Engineering Design: Electrical and electronic engineers often work with both unit systems when designing international systems.

• Standards Compliance: Electrical codes may specify requirements in AWG or mm², requiring conversion to ensure proper installations.

Tips for Accurate Conversion

• Always use reliable conversion charts for exact matches.

• Consider the wire type (solid vs. stranded), as actual diameters may vary slightly.

• Don’t rely solely on formulas for safety-critical applications—use manufacturer data when available.

Frequently Asked Questions

How do I convert mm² to AWG accurately?

Use a conversion chart for the most accurate results. While formulas exist, the logarithmic nature of AWG makes direct calculation less practical for everyday use.

Why does mm² not convert directly to AWG?

AWG is based on wire diameter using a logarithmic scale, while mm² measures area directly. This structural difference prevents straightforward linear conversion.

Can stranded and solid wires have different AWG values?

No. The AWG number stays the same, but stranded wires may have slightly more insulation or different resistance characteristics due to air gaps between strands.

What AWG is 2.5 mm²?

2.5 mm² is approximately equal to 13 AWG. This size is commonly used for household wiring in circuits with higher current loads.

Is it safe to round wire size when converting?

No. For electrical safety, always use the closest larger wire size to handle the current safely, especially if exact AWG sizes aren’t available in your region.