Gauge to MM Calculator
Convert gauge values to millimeters for wire, sheet metal, plastic film, and jewelry. Choose the correct standard to get accurate thickness measurements.
No more confusion between wire gauges and sheet metal gauges. Select your material type and get exact millimeter measurements.
Gauge Converter
Enter gauge number or thickness value
Different materials use different gauge standards
Thickness Results
Enter gauge and select material
Understanding Gauge Measurements
Gauge numbers can be really confusing. You might think 20 gauge means the same thickness everywhere, but that's not how it works. Different industries and materials use completely different gauge systems. What works for wire won't work for sheet metal, and jewelry has its own standards too.
This calculator helps you convert those gauge numbers into actual measurements you can understand. Just pick your material type and get the thickness in millimeters, inches, or whatever unit you need.
Why Gauge Standards Matter
The problem with gauges is they're not standardized across materials. A 20 gauge wire is much thinner than 20 gauge sheet metal. Using the wrong chart can lead to expensive mistakes in manufacturing or construction.
- AWG 18 wire = 1.02 mm diameter
- Steel sheet gauge 18 = 1.21 mm thick
- Jewelry gauge 18 = 1.02 mm thick
Same gauge number, but different thicknesses depending on what you're measuring.
How the Conversion Works
The calculator uses lookup tables based on official industry standards. There's no fancy math involved - just reliable reference data.
For reverse conversions (thickness to gauge), we find the closest matching value in the chart.
Steel Sheet Metal Gauge Chart
Here's a common reference for steel sheet metal gauges:
| Gauge | MM | Inch |
|---|---|---|
| 6 | 5.16 | 0.2031 |
| 7 | 4.76 | 0.1875 |
| 8 | 4.19 | 0.1649 |
| 9 | 3.78 | 0.1488 |
| 10 | 3.42 | 0.1345 |
| 11 | 3.05 | 0.1201 |
| 12 | 2.68 | 0.1055 |
| 13 | 2.41 | 0.0949 |
| 14 | 1.99 | 0.0784 |
| 15 | 1.82 | 0.0717 |
| 16 | 1.59 | 0.0626 |
| 17 | 1.37 | 0.0539 |
| 18 | 1.21 | 0.0478 |
| 19 | 1.09 | 0.0430 |
| 20 | 0.91 | 0.0359 |
| 21 | 0.81 | 0.0320 |
| 22 | 0.71 | 0.0280 |
| 23 | 0.64 | 0.0252 |
| 24 | 0.56 | 0.0220 |
| 25 | 0.51 | 0.0201 |
| 26 | 0.46 | 0.0181 |
| 27 | 0.41 | 0.0161 |
| 28 | 0.36 | 0.0142 |
| 29 | 0.33 | 0.0130 |
| 30 | 0.31 | 0.0122 |
Always double-check your gauge standard before ordering materials. A small mix-up can cause big problems in your project.