Metric to AWG / MCM Conversion Guide
Introduction
Metric wire sizes are expressed in square millimeters (mm²), which represent the conductor’s cross-sectional area. In North America, wire sizes are defined using the American Wire Gauge (AWG) system for smaller conductors, where a lower number means a larger wire. For larger conductors, the system shifts to MCM (thousand circular mils), also referred to as kcmil.
If you’re working with international drawings or importing equipment built to metric standards, having a quick reference for conversions is essential. The chart below provides the nearest standard equivalents.
Metric (mm²) to AWG / MCM Conversion Table
- 0.08 mm² = 28 AWG (fine hook-up wire)
- 0.14 mm² = 26 AWG
- 0.20 mm² = 24 AWG
- 0.25 mm² ≈ 24 AWG (approximate)
- 0.34 mm² = 22 AWG
- 0.50 mm² = 20 AWG
- 0.75 mm² ≈ 19 AWG (approximate)
- 1.00 mm² = 18 AWG
- 1.50 mm² = 16 AWG
- 2.50 mm² = 14 AWG
- 4.00 mm² = 12 AWG
- 6.00 mm² = 10 AWG
- 10 mm² = 8 AWG
- 16 mm² = 6 AWG
- 25 mm² = 4 AWG
- 35 mm² = 2 AWG
- 50 mm² = 1/0 AWG
- 70 mm² = 2/0 AWG
- 95 mm² = 3/0 AWG
- 120 mm² = 4/0 AWG
- 150 mm² = 250 MCM (large power cable)
- 185 mm² ≈ 350 MCM (approximate)
- 240 mm² ≈ 450 MCM (approximate)
- 300 mm² ≈ 550 MCM (approximate)
Notes:
- Values shown are the nearest standard equivalents based on IEC and NEC cross-reference tables. Exact dimensions can vary depending on manufacturer, conductor stranding, and insulation type.
- Sizes 250 MCM and above are expressed in thousand circular mils (MCM or kcmil).
- AWG follows an inverse scale, meaning smaller numbers indicate larger conductors.
How to Use This Chart
Locate your metric size in the left column and read across to find the closest AWG or MCM equivalent. If your exact size is not listed, it’s standard practice to round up to the next larger size to maintain safe ampacity.
For example:
- A 2.5 mm² conductor corresponds to 14 AWG
- A 150 mm² conductor corresponds to 250 MCM
AWG vs. MCM: Key Differences
AWG (American Wire Gauge):
Used for smaller conductors, typically ranging from 30 AWG (very fine wire) up to 4/0 AWG (approximately 107 mm²). The scale is logarithmic and inverse.
MCM (Thousand Circular Mils / kcmil):
Used for larger conductors starting at 250 MCM and above. One circular mil represents the area of a circle with a diameter of one mil (0.001 inch). So, a 250 MCM conductor has a cross-sectional area of 250,000 circular mils.
Final Thoughts
This conversion chart is a practical starting point when working between metric and North American wire standards. Whether you’re reviewing international specifications or sourcing cable for a mixed-standard project, it helps bridge the gap quickly.
That said, final conductor selection should always be verified against applicable standards such as NEC or IEC, along with manufacturer data for voltage rating, temperature rating, and ampacity.
Need Help Sourcing Wire?
We stock a full range of copper and aluminum conductors, including:
- 30 AWG through 4/0 AWG
- 250 MCM through 1000 MCM and larger
Available in multiple colors, stranding types, and spool sizes, with nationwide shipping from Tulsa, Oklahoma. Reach out for pricing or help selecting the right cable for your application.
