Sheet metal gauge converter
Convert a gauge number to a real thickness. Pick the metal first: 16 gauge steel and 16 gauge aluminum are not the same thickness.
That's 1.01× as thick as a steel cabinet, while structural plate is 3.3× thicker. A square meter of steel that thick weighs about 11.92 kg.
What it means
How thick is that?
Gauge tables are nominal. Real sheet is supplied to a tolerance, and mill certificates quote the measured thickness rather than the gauge.
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Your thickness in every unit
Learn
Three things worth knowing
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Higher gauge is thinner
10 gauge steel is 3.4 mm; 20 gauge is 0.9 mm. The number counts drawing passes, and each pass made the sheet thinner.
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Counting draws through a die
Wire and sheet were thinned by pulling them through successively smaller dies. The gauge number recorded how many passes it took, which is why the scale is backwards and uneven.
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Always state the metal
Ordering "16 gauge" without saying steel or aluminum can be 18% out on thickness, and far more on strength.
Shortcuts
Popular thickness conversions
Background
About gauge numbers
Gauge is not a unit. It is a position in a table, and each metal has its own table: 16 gauge steel is 1.52 mm, 16 gauge aluminum 1.29 mm, and 16 gauge stainless 1.59 mm.
The numbers also run backwards — a higher gauge is thinner — because they once counted how many times the metal had been drawn through a die.