Sheet Metal Gauge Calculator

What the sheet metal gauge calculator does

Gauge numbers run backward, so a lower gauge is a thicker sheet, and the same gauge means a different thickness in each material. 16 gauge steel is 0.0598 in, 16 gauge galvanized is 0.0635 in, and 16 gauge aluminum is only 0.0508 in. The sheet metal gauge calculator looks up the right table for the material, converts to millimeters, and adds the weight so you can order and lift the sheet with confidence.

Gauge to mm conversion

Each material has its own gauge table. The calculator reads the thickness, then:

Standard steel follows the Manufacturers Standard Gauge, galvanized has its own slightly thicker table, stainless uses its common sheet gauge, and aluminum follows the Brown and Sharpe gauge.

Sheet metal gauge calculator example

A 4 by 8 ft sheet of 16 gauge standard steel:

That is 36.3 kg per sheet. An 18 gauge stainless sheet, 48 by 120 in, is 0.050 in (1.27 mm) thick and weighs 84 lb.

How to use the sheet metal gauge calculator

Choose the material: standard steel, galvanized, stainless, or aluminum. Enter the gauge number, from 7 to 30. To get the weight of a sheet, enter its length and width in inches, such as 96 by 48 for a standard 4 by 8 sheet. Press Calculate to read the thickness and the weights.

Reading sheet metal gauge thickness

Gauge is a nominal size; mills supply sheet within a tolerance, so measure with calipers when the fit is tight. The weight per square foot lets you price sheet sold by weight and plan handling: one person can carry a 4 by 8 sheet of 20 gauge steel, but 10 gauge at about 180 lb needs two people or a lift. Check that drawings and quotes use the same gauge system, since a 16 gauge call-out means different things in steel and aluminum.

When to use a gauge thickness chart

• Converting a gauge call-out to mm for a metric drawing
• Picking ductwork, roofing, or enclosure sheet
• Pricing sheet sold by weight
• Checking bend tooling and fastener lengths
• Comparing steel and aluminum at the same gauge

Common sheet metal gauge calculator mistakes

• Using the steel table for aluminum. Each material has its own gauge.
• Assuming higher gauge is thicker. It is the opposite.
• Ignoring tolerance. Measure when the fit is critical.
• Mixing wire gauge and sheet gauge. Wire uses AWG; steel sheet does not.

Tips for using a gauge thickness chart

• Write the decimal thickness on drawings next to the gauge.
• Check fastener grip ranges against the real thickness.
• Order a sample when switching suppliers for tight fits.

Related sheet metal tools

Once you know the thickness, the bend allowance calculator sizes the flat blank, the sheet metal weight calculator weighs any thickness and size, and the aluminum weight calculator covers aluminum plate and bar.

Steel gauge chart versus galvanized and stainless

The Manufacturers Standard Gauge for steel sheet is based on weight: 16 gauge is defined as 2.5 lb per square foot, and the thickness follows from a steel weight of 41.82 lb per square foot per inch. Galvanized sheet uses the same idea but adds the zinc coating, so each gauge is a few thousandths of an inch thicker. Stainless sheet in common use follows round fractional values, such as 0.0625 in for 16 gauge, and weighs a little more per inch because of its density. When a fabricator bends the sheet, that thickness sets the bend allowance, so convert first and then use the bend allowance calculator with the exact value.

Aluminum gauge thickness and weight

Aluminum follows the Brown and Sharpe gauge, the same series used for American wire gauge, so 16 gauge aluminum is 0.0508 in, about 15% thinner than 16 gauge steel. Aluminum also weighs about a third as much, so a 4 by 8 sheet of 16 gauge aluminum weighs under 23 lb against 80 lb for steel. Many aluminum suppliers now quote decimal thickness instead of gauge to avoid confusion. For aluminum plate and bar beyond the gauge range, the aluminum weight calculator takes any size.

Sheet metal gauge chart

Thickness in inches for common gauges:

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