All Unit Conversions

Sheet Metal Gauge Chart

The same gauge number means a different thickness for steel, galvanized steel, stainless steel and aluminium. This chart gives all four, calculated from each gauge system’s definition, in inches and millimetres.

Standards and method

Thicknesses are calculated from each gauge system’s definition (weight per square foot, the 1893 fractions, or the AWG formula) and cross-checked against a second published gauge table.

Maintained by Miguel Coelho. Updated . See our editorial policy.

Preview of the printable Sheet Metal Gauge Chart

Printable sheet metal gauge chart

Gauge 3 to 30 in inches and mm for steel, galvanized steel, stainless steel and aluminium. Includes the exact definition, formulas, a worked example and sources. Conversion values are checked against the defining constants, and reference data is cited to its source, before the PDF is published.

Free to print, share and use in teaching materials with attribution (CC BY 4.0).

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Full sheet metal gauge chart

Gauge 3 to 30 in inches and mm for steel, galvanized steel, stainless steel and aluminium. These are the same tables as the printable PDF. For: Fabricators, HVAC and duct installers, welders, engineers and buyers.

Key relationship
Steel gauge is defined by weight: thickness (in) = weight (lb/ft²) ÷ 41.82
Formula
Galvanized = (steel weight + 2.5 oz/ft²) ÷ 41.82; aluminium = AWG diameter
Reverse
Weight (lb/ft²) = thickness (in) × 41.82 for steel
Worked example
16 gauge: steel 0.0598 in, galvanized 0.0635 in, stainless 0.0625 in, aluminium 0.0508 in
Rounding
Nominal thicknesses to 4 decimal places of an inch. The same gauge number means a different thickness in each system, so always state the thickness.

Sheet metal gauge thickness

Many stainless suppliers quote the steel (MSG) decimals instead of the 1893 gauge; check the thickness on the mill certificate.

Sheet metal gauge thickness
GaugeSteel (in)Steel (mm)Galvanized (in)Galvanized (mm)Stainless (in)Stainless (mm)Aluminium (in)Aluminium (mm)
30.23916.074——0.25006.350——
40.22425.694——0.23445.953——
50.20925.314——0.21885.556——
60.19434.935——0.20315.1590.16204.115
70.17934.555——0.18754.7620.14433.665
80.16444.1760.16814.2710.17194.3660.12853.264
90.14953.7960.15323.8910.15633.9690.11442.906
100.13453.4160.13823.5110.14063.5720.10192.588
110.11963.0370.12333.1320.12503.1750.09072.305
120.10462.6570.10842.7520.10942.7780.08082.053
130.08972.2780.09342.3730.09382.3810.07201.828
140.07471.8980.07851.9930.07811.9840.06411.628
150.06731.7080.07101.8030.07031.7860.05711.450
160.05981.5180.06351.6130.06251.5880.05081.291
170.05381.3670.05751.4610.05631.4290.04531.150
180.04781.2150.05161.3100.05001.2700.04031.024
190.04181.0630.04561.1580.04381.1110.03590.912
200.03590.9110.03961.0060.03750.9520.03200.812
210.03290.8350.03660.9300.03440.8730.02850.723
220.02990.7590.03360.8540.03130.7940.02530.644
230.02690.6830.03060.7780.02810.7140.02260.573
240.02390.6070.02760.7020.02500.6350.02010.511
250.02090.5310.02470.6260.02190.5560.01790.455
260.01790.4560.02170.5500.01880.4760.01590.405
270.01640.4180.02020.5120.01720.4370.01420.361
280.01490.3800.01870.4750.01560.3970.01260.321
290.01350.3420.01720.4370.01410.3570.01130.286
300.01200.3040.01570.3990.01250.3180.01000.255

Steel sheet weight by gauge

Steel sheet weight by gauge (part 1)
Gaugelb/ft²kg/m²Galvanized lb/ft²Galvanized kg/m²
310.000048.82——
49.375045.77——
58.750042.72——
68.125039.67——
77.500036.62——
86.875033.577.031334.33
96.250030.526.406331.28
105.625027.465.781328.23
115.000024.415.156325.18
124.375021.364.531322.12
133.750018.313.906319.07
143.125015.263.281316.02
152.812513.732.968814.49
162.500012.212.656312.97
Steel sheet weight by gauge (part 2)
Gaugelb/ft²kg/m²Galvanized lb/ft²Galvanized kg/m²
172.250010.992.406311.75
182.00009.762.156310.53
191.75008.541.90639.31
201.50007.321.65638.09
211.37506.711.53137.48
221.25006.101.40636.87
231.12505.491.28136.26
241.00004.881.15635.65
250.87504.271.03135.04
260.75003.660.90634.42
270.68753.360.84384.12
280.62503.050.78133.81
290.56252.750.71883.51
300.50002.440.65633.20

Sources for this chart

Thicknesses are calculated from each gauge system’s definition (weight per square foot, the 1893 fractions, or the AWG formula) and cross-checked against a second published gauge table.

  • Manufacturers' Standard Gauge for steel sheet — Gauge defined by weight: 41.82 lb/ft² per inch of thickness; galvanized adds 2.5 oz/ft² of zinc
  • US Standard Gauge (Act of 3 March 1893) — Gauge thickness as a fraction of an inch; still used for stainless steel sheet
  • Brown & Sharpe gauge (ASTM B258) — Same as AWG; used for aluminium, copper and brass sheet

Related Converters & Charts

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Coelho, M. (2026). Sheet Metal Gauge Chart (Edition 2.0). All Unit Conversions. https://allunitconversions.com/sheet-metal-gauge-chart

Sheet Metal Gauge Chart FAQs

Common questions about the sheet metal gauge chart.

How thick is 16 gauge steel?

16 gauge steel sheet is 0.0598 in (1.518 mm). Galvanized 16 gauge is 0.0635 in, stainless is 0.0625 in and aluminium is 0.0508 in.

Is 18 gauge thicker than 16 gauge?

No. A higher gauge number is thinner: 18 gauge steel is 0.0478 in, 16 gauge is 0.0598 in.

Why is aluminium gauge thinner than steel gauge?

Aluminium uses the Brown & Sharpe (AWG) gauge, while steel uses the Manufacturers’ Standard Gauge, which is based on weight. 10 gauge aluminium is 0.1019 in; 10 gauge steel is 0.1345 in.

Can I download this chart as a PDF, CSV, or JSON?

Yes. Use the Download A4 PDF or US Letter PDF buttons for a printable version, or download the same tables as CSV or JSON from the links on this page.