Sheet Metal Gauge
Gauge to thickness in mm and inches — and back — for steel, galvanized, stainless, and aluminium.
Which gauge,
for which metal.
The same number means different thicknesses.
Where the thicknesses come from
Uncoated steel uses the Manufacturers' Standard Gauge (MSG); galvanized sheet uses the MSG galvanized table, which is slightly thicker because it includes the zinc coating; stainless sheet has its own table. These are lookups, not formulas, so they are kept as a versioned dataset whose version is shown with every result. Aluminium is different: it follows the Brown & Sharpe (AWG) series, which is a formula — thickness = 0.005 × 92^((36 − gauge) ÷ 39) in — so it is computed exactly. 16 gauge is 1.52 mm in steel, 1.61 mm galvanized, 1.59 mm stainless, and 1.29 mm aluminium.
Thickness to gauge, and weight per area
Entering a thickness returns the nearest gauge in that material and how far off it is, because real sheet is ordered by gauge but measured in millimetres. Weight per area is thickness × a typical density (7,850 kg/m³ steel, 8,000 stainless, 2,710 aluminium) — an estimate for planning; supplier weights include tolerance and coating.
What this utility does not do
No wire gauges (SWG, AWG for wire diameter), no copper or brass sheet tables, no tolerances. The tables are pending a reviewer's check against supplier or ASTM references. Inputs stay in your browser; the same four anonymous usage counts as the rest of the site apply.