Sheet Metal Gauge Converter

That depends on the material, which is why the question has no single answer. Uncoated steel sheet at 16 gauge is 1.519 mm (0.0598 in) under the Manufacturers' Standard Gauge; galvanized steel at the same number is 1.613 mm (0.0635 in) because the published figure includes the zinc coating; aluminium at 16 Brown & Sharpe is 1.290 mm (0.0508 in). Always state the material with the gauge number.

The numbering comes from wire drawing, where the number counted how many times the stock had been pulled through a die. Each pass made it thinner, so a higher count meant a thinner product. Sheet inherited the convention, which is why the series runs backwards and why no formula reproduces it — the steps are historical, not calculated.

Order to the thickness in millimetres, not to the gauge number. This calculator will name the nearest published row and print that row's exact thickness beside it, so you can see how far your requirement sits from a real stock size — but the gauge number itself is not a specification, and rounding to it silently changes the part.

Because the published table does not print them for that material. The galvanized series starts at 8 and stops at 32; the uncoated steel series runs 3 to 36; Brown & Sharpe runs 1 to 36. Where a number is missing there is no defined thickness, so the calculator says so instead of extrapolating a plausible-looking value that no standard would back.