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About this gauge chart

This is an independent reference site. It exists for one reason: a gauge number is not a thickness, and the four sheet metals in everyday use each read it differently. The charts here put the four systems side by side so a number quoted for one metal is never read off another metal's table.

Where the numbers come from

Every thickness on this site follows the published standard gauge table for its metal:

• Steel: Manufacturers' Standard Gauge (ASTM A568)
• Galvanized: MSG + 0.0037 in zinc allowance (ASTM A653); no gauge 7 published
• Stainless steel: Stainless sheet gauge series, fraction-based (ASTM A480)
• Aluminum: Brown & Sharpe / AWG (ASTM B209), t = 0.005 x 92^((36-n)/39)

The tables were cross-checked across independent published supplier charts; two complete published tables agree on every cell, and the galvanized and aluminum columns were additionally verified against their governing rules — galvanized is the steel value plus 0.0037 in at every row, and aluminum matches the Brown & Sharpe formula at every row. Where no value is published — 7 gauge galvanized — the chart shows a dash instead of a calculated number.

Sources consulted

• reuven.tools/reference/sheet-metal-gauges (adjudicated table, read 2026-11-10)
• baouch.fr sheet metal gauge chart (read 2026-11-10) — inch table identical cell-for-cell
• yijinsolution.com gauge chart — fragments agree (steel 16 ga 0.0598; stainless 16 ga 0.0625, 30 ga 0.0125)

This site is not affiliated with ASTM International or with any of the sources above; the standards are named so you can verify the values against the same published tables. Values are nominal thicknesses — for work where exact thickness decides the fit, confirm with your supplier and measure the delivered sheet.