Sheet metal gauge chart: steel, stainless, and aluminum in inches and millimetres

How thick is each sheet metal gauge?

It depends on the metal, and that's the trap. 16 ga carbon steel is 0.0598″ (1.52 mm). 16 ga stainless is 0.0625″ (1.59 mm). 16 ga aluminum is 0.0508″ (1.29 mm). 16 ga galvanized is 0.0635″ (1.61 mm). One gauge number, four different thicknesses, and the spread gets worse at the heavy end of the table.

Two rules carry you through every chart on this page. First, a bigger gauge number means thinner metal: 7 ga steel is 0.1793″ and 26 ga is 0.0179″, a tenfold drop. Second, a gauge number without a material named beside it isn't a spec; it's a guess. The four tables below cover the full practical range, 7 through 26 ga, in decimal inches and millimetres, with sheet weights for steel.

Why does the same gauge number mean different thicknesses?

Because each metal kept its own historical table, and none of them talk to each other. Carbon steel uses the Manufacturers' Standard Gauge, which is really a weight system: steel sheet at 41.82 lb per square foot per inch of thickness, with each gauge number assigned a weight. Stainless runs its own series descended from the old US Standard gauge of 1893, which is why its numbers land on clean fractions: 11 ga is exactly 1/8″ and 16 ga is exactly 1/16″. Aluminum uses the Brown and Sharpe gauge, a geometric series drawn up for wire back in 1857. Galvanized rides on the steel table with a zinc allowance added on top.

The full story of how sheet, gauge, and plate naming fits together lives in our sheet vs plate guide. The short version: gauge talk fades out around 3/16″, and everything thicker goes by fraction or decimal, 1/4″, 3/8″, 1/2″ and up.

What's the gauge chart for carbon and galvanized steel?

Carbon steel sheet runs from 0.1793″ (4.55 mm) at 7 ga down to 0.0179″ (0.45 mm) at 26 ga. The weight column is exact by definition, since the gauge is the weight. That makes panel math easy before you order: a 4 ft × 8 ft sheet of 16 ga is 2.5 lb times 32 square feet, so 80 lb.

Galvanized sheet gets its own slightly thicker table. The old Galvanized Sheet Gauge set each number to the bare-steel thickness plus 0.0037″ of zinc allowance. That allowance is 1.25 oz of zinc per square foot on each face, 2.5 oz total, converted at the same 41.82 lb basis. That's why 16 ga galvanized is 0.0635″ where bare 16 ga steel is 0.0598″. The series starts at 8 ga; there's no standard 7 ga galvanized. Mills today order galvanized by decimal thickness and coating class, and the gauge label is a holdover, which is one more reason the decimal is the number to trust.

Our galvanized rack reads straight off that table: the product titles run 26GA .0217 through 16GA, decimal included, so what you click is what gets sheared.

What's the gauge chart for stainless and aluminum?

Stainless runs thicker than carbon steel at the same gauge number, and aluminum runs thinner. 16 ga makes the point: 0.0625″ in stainless, 0.0598″ in carbon, 0.0508″ in aluminum. Stainless first:

Aluminum follows the Brown and Sharpe series, the thinnest of the four at any given number:

On weight, aluminum runs about a third of steel at the same thickness: figure 14.1 lb per square foot per inch against the steel table's 41.82. A 16 ga aluminum sheet is lighter still at roughly 0.72 lb per square foot against 2.5 for 16 ga steel, because the aluminum gauge is thinner on top of the lighter metal. That's a big part of why bent aluminum work leans on 5052; our aluminum buying guide covers which alloy carries which job.

Watch the .063″ callout when you switch materials. 16 ga stainless (0.0625″) and 14 ga aluminum (0.0641″) both answer to the .063-.064″ number on a drawing. On our racks that's the 16GA .063 stainless sheet and the 14GA .064 aluminum sheet, two different gauge numbers for nearly the same thickness. Ask for "16 ga aluminum" against a .063″ drawing and you'll get 0.051″, about 20% thin. When the drawing gives a decimal, match the decimal and ignore the gauge number.

Brass and copper sit this system out almost entirely. Sheet in both metals sells by decimal inches or fractions: our brass sheet starts at .0400″ and steps through 1/16″, 1/8″, 3/16″, and 1/4″, and copper starts at .027″ and climbs the same fraction ladder. Roofing copper goes by weight instead, in ounces per square foot, where 16 oz works out to about 0.0216″ thick. The one place a brass gauge number does show up is the Brown and Sharpe series, the same table as aluminum.

What gauge does your project need?

Pick by what the part has to survive, then let the chart hand you the decimal. These are the calls we make at the counter most weeks:

Working from a metric drawing? Divide by 25.4 and shop the decimal. 1.5 mm lands on 16 ga steel (1.52 mm). 2 mm sits closest to 14 ga stainless (1.98 mm) or 12 ga aluminum (2.05 mm). 3 mm falls between 11 ga steel (3.04 mm) and 1/8″ (3.18 mm). Then read the decimal in the product title before you order; that's the coil we're actually cutting from, and thickness comes as rolled. Our ±1/8″ cut tolerance applies to the width and length we shear, not the thickness.

What sheet do we stock by gauge, and what does it cost?

Every range here is on the rack as of June 2026 and cuts to your width and length in inches, free, to ±1/8″. On the carbon steel rack, cold rolled A1008 covers 24, 22, 20, and 18 ga, and hot rolled covers 16 ga (.059″) and 14 ga (.075″), labelled A36, the US name buyers search for. From 1/8″ up, carbon drops the gauge talk and sells by fraction in 44W. Galvanized A653 runs 26, 24, 22, 20, 18, and 16 ga. Stainless 304 2B runs 24, 22, 20, 18, 16, and 14 ga, then 1/8″ and 3/16″, with 316 2B from 1/8″ to 3/8″ for salt and chemicals. Aluminum 5052 H32 runs 20, 18, 16, 14, 12, and 11 ga, then 1/8″ through 1/2″, with 6061 T6 in fractions from 1/8″ for machining and welding.

All three of those are "16 gauge", and none are the same thickness; the price follows the metal, not the number. Prices update daily, and the full June 2026 board, bar stock included, lives in our metal prices guide. Type a width and a length on any sheet page and the price shows up. Volume discounts of 5-15% apply automatically, and an order placed by 1pm Atlantic on a business day usually ships the next business day.

Need a gauge the rack skips, or a thickness to match a metric spec? Send a quote request with the decimal and we'll point you at the nearest stock size or source it; sourcing runs 2-21 days, and you'll see the price before you commit.