Free tool
Gauge to mm
A US drawing sometimes gives sheet thickness in "gauge" instead of mm. Convert below — for steel sheet (Manufacturers' Standard Gauge).
Recurring parts or a prototype?
From a one-off prototype to recurring series of hundreds. Send your drawing and you'll have a quote within 24 hours.
Full table (steel, 3–28 gauge)
| Gauge | Thickness (mm) |
|---|---|
| 3 ga | 6.073 mm |
| 4 ga | 5.695 mm |
| 5 ga | 5.314 mm |
| 6 ga | 4.935 mm |
| 7 ga | 4.554 mm |
| 8 ga | 4.176 mm |
| 9 ga | 3.797 mm |
| 10 ga | 3.416 mm |
| 11 ga | 3.038 mm |
| 12 ga | 2.657 mm |
| 13 ga | 2.278 mm |
| 14 ga | 1.897 mm |
| 15 ga | 1.709 mm |
| 16 ga | 1.519 mm |
| 17 ga | 1.367 mm |
| 18 ga | 1.214 mm |
| 19 ga | 1.062 mm |
| 20 ga | 0.912 mm |
| 21 ga | 0.836 mm |
| 22 ga | 0.759 mm |
| 23 ga | 0.683 mm |
| 24 ga | 0.607 mm |
| 25 ga | 0.531 mm |
| 26 ga | 0.455 mm |
| 27 ga | 0.417 mm |
| 28 ga | 0.378 mm |
Why steel only?
"Gauge" isn't a fixed unit — it's a numbering system that means something different per material: steel sheet generally follows the Manufacturers' Standard Gauge (the table above), while aluminium and stainless in the US often follow the Brown & Sharpe gauge system instead — the same number, a different thickness. That second system is less consistently published, so this tool deliberately leaves it out rather than showing a thickness that might be wrong.
Working from a US drawing in aluminium or stainless gauge? Ask the customer to confirm the thickness directly in mm, or send the drawing — we'll check it. Inside FerroxX we always work in mm anyway.
Not sure about a dimension on a drawing?Send it over