The Gauge To Mm Calculator helps convert metal sheet gauge numbers into their exact thickness in millimeters. This tool is especially useful in fields like construction, engineering, fabrication, and automotive work, where knowing the precise thickness of a material is necessary for safety, fit, and function.
This calculator is part of the material thickness and metric conversion calculator category.
Different materials have different gauge-to-millimeter relationships. For example, a 16-gauge sheet of steel has a different thickness than a 16-gauge sheet of aluminum. Since the gauge system is not linear and varies by material type, the calculator uses standardized lookup tables based on ASTM (American Society for Testing and Materials) or other industrial standards to provide accurate results.
formula
There is no fixed formula to convert gauge to mm because gauge values differ by material type (e.g., steel, stainless steel, aluminum). Instead, it is done using standardized reference tables for each material.
Here is a standard Sheet Steel Gauge to mm (ASTM – U.S. Standard) reference:
| Gauge | Thickness (mm) |
|---|---|
| 10 | 3.416 |
| 11 | 3.023 |
| 12 | 2.667 |
| 13 | 2.381 |
| 14 | 1.897 |
| 16 | 1.613 |
| 18 | 1.214 |
| 20 | 0.912 |
| 22 | 0.754 |
| 24 | 0.610 |
| 26 | 0.455 |
Calculator Logic:
- Accepts input: gauge_number
- Checks material type: steel, aluminum, galvanized steel, etc.
- Uses a material-specific lookup table
- Returns the correct thickness in millimeters
Optional: Approximate Formula (for steel only)
If you must use a formula (for quick estimates), a rough empirical formula is:
mm = 10^( ( -gauge + 30 ) / 20 )
This formula provides only an approximate result and should not be used for engineering or structural applications.
Quick Reference Table for Multiple Materials
To make it easier to use, here’s a comparison table showing thickness in mm for common materials by gauge.
| Gauge | Steel (mm) | Galvanized Steel (mm) | Aluminum (mm) |
|---|---|---|---|
| 10 | 3.416 | 3.571 | 2.588 |
| 12 | 2.667 | 2.753 | 2.052 |
| 14 | 1.897 | 1.994 | 1.626 |
| 16 | 1.613 | 1.613 | 1.290 |
| 18 | 1.214 | 1.311 | 1.024 |
| 20 | 0.912 | 1.006 | 0.812 |
| 22 | 0.754 | 0.853 | 0.644 |
| 24 | 0.610 | 0.701 | 0.511 |
Always select the correct material type when using a calculator to avoid incorrect thickness measurements.
Example
Let’s look at how to use the Gauge To Mm Calculator with an example.
Suppose you are working with a 14-gauge sheet of steel.
Step 1: Enter the gauge number = 14
Step 2: Choose material = steel
Step 3: Look up or calculate using the table
From the standard sheet steel chart:
14 gauge = 1.897 mm
Now, if you were using aluminum:
Step 1: Gauge = 14
Step 2: Material = aluminum
Step 3: Lookup result = 1.626 mm
Final Answer:
14 gauge steel = 1.897 mm
14 gauge aluminum = 1.626 mm
Most Common FAQs
Gauge is a historical measurement system developed separately for different materials. Because of the different densities and production methods of metals, the thickness associated with a given gauge number varies between materials like steel, aluminum, and galvanized steel.
No. Each type of metal has its own gauge-to-thickness relationship. Using the wrong table can result in incorrect calculations and potentially unsafe material usage.
Lookup tables are always more accurate and are based on industry standards. While formulas can offer rough estimates, they are not precise and should only be used when tables are unavailable or precision is not critical.