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Sheet Metal Gauge Chart
16 gauge, four metals: Steel 0.0598 in (1.519 mm) · Galvanized 0.0635 in (1.613 mm) · Stainless steel 0.0625 in (1.587 mm) · Aluminum 0.0508 in (1.29 mm).
Same gauge number, four different thicknesses. The full chart for gauges 7–30 is below.
This chart covers gauges 7 through 30 for the four sheet metals you are most likely to be quoted: carbon steel, galvanized steel, stainless steel, and aluminum. Read across a row to see how far apart the systems sit at the same gauge number. Read down a column to see one metal's full range, from heavy 7 gauge plate-like sheet at about 0.18 inches down to 30 gauge foil-like stock at about 0.012 inches.
Two habits will keep you out of trouble. First, never convert a gauge from one metal using another metal's chart — at 16 gauge the spread between aluminum and galvanized is 0.0127 inches, about 25 percent of the aluminum value. Second, when a drawing or a supplier quote gives a decimal thickness instead of a gauge, use the nearest-gauge table further down this page: metric stock is sold by the millimetre, and 1.5 mm, for example, sits closest to 16 gauge in steel and galvanized, 15 gauge in stainless, and between 14 and 15 gauge in aluminum.
Gauge converter
Full gauge chart — inches and millimetres
| Gauge | Steel | Galvanized | Stainless | Aluminum | Relative thickness |
|---|---|---|---|---|---|
| 7 | 0.1793 | — | 0.1875 | 0.1443 | |
| 8 | 0.1644 | 0.1681 | 0.1719 | 0.1285 | |
| 9 | 0.1495 | 0.1532 | 0.1563 | 0.1144 | |
| 10 | 0.1345 | 0.1382 | 0.1406 | 0.1019 | |
| 11 | 0.1196 | 0.1233 | 0.1250 | 0.0907 | |
| 12 | 0.1046 | 0.1084 | 0.1094 | 0.0808 | |
| 13 | 0.0897 | 0.0934 | 0.0938 | 0.0720 | |
| 14 | 0.0747 | 0.0785 | 0.0781 | 0.0641 | |
| 15 | 0.0673 | 0.0710 | 0.0703 | 0.0571 | |
| 16 | 0.0598 | 0.0635 | 0.0625 | 0.0508 | |
| 17 | 0.0538 | 0.0575 | 0.0563 | 0.0453 | |
| 18 | 0.0478 | 0.0516 | 0.0500 | 0.0403 | |
| 19 | 0.0418 | 0.0456 | 0.0438 | 0.0359 | |
| 20 | 0.0359 | 0.0396 | 0.0375 | 0.0320 | |
| 21 | 0.0329 | 0.0366 | 0.0344 | 0.0285 | |
| 22 | 0.0299 | 0.0336 | 0.0313 | 0.0253 | |
| 23 | 0.0269 | 0.0306 | 0.0281 | 0.0226 | |
| 24 | 0.0239 | 0.0276 | 0.0250 | 0.0201 | |
| 25 | 0.0209 | 0.0247 | 0.0219 | 0.0179 | |
| 26 | 0.0179 | 0.0217 | 0.0188 | 0.0159 | |
| 27 | 0.0164 | 0.0202 | 0.0172 | 0.0142 | |
| 28 | 0.0149 | 0.0187 | 0.0156 | 0.0126 | |
| 29 | 0.0135 | 0.0172 | 0.0141 | 0.0113 | |
| 30 | 0.0120 | 0.0157 | 0.0125 | 0.0100 |
The four gauge systems
Carbon steel — Manufacturers' Standard Gauge
The baseline system, and the one most people picture when they say a gauge number. It is defined by weight under ASTM A568: thickness in inches times 41.82 gives the weight in pounds per square foot, which is why the steel chart on this site carries a weight column and the others do not. Use it for mild and carbon steel sheet.
Galvanized steel — MSG plus the zinc layer
Galvanized sheet is carbon steel with a zinc coating, and the published gauge includes that coating: every value is the matching steel gauge plus 0.0037 inches, per ASTM A653 practice. The series starts at 8 gauge — no 7 gauge galvanized is published. Use it for ductwork, roofing, and anything that lives outdoors.
Stainless steel — the fraction series
Stainless sheet follows its own older series under ASTM A480, and its published decimal values are renderings of simple fractions: 0.1875 at 7 gauge, 0.0625 — exactly 1/16 inch — at 16 gauge. It reads thicker than carbon steel at every shared gauge, by about 5 percent at 16 gauge. Use it for food, medical, marine, and kitchen work.
Full stainless steel gauge chart →
Aluminum — Brown & Sharpe
Aluminum borrows the Brown & Sharpe wire gauge under ASTM B209. The series is a formula, not a lookup: thickness equals 0.005 times 92 raised to (36 minus the gauge number) over 39. Aluminum is the thinnest reading of the four at every gauge and, at roughly a third of steel's density, by far the lightest sheet at any given gauge.
Nearest gauge for metric thicknesses
Metric sheet is sold by the millimetre. This table finds the closest published gauge in each metal for common metric sizes — computed from the same chart above, so you can see the actual thickness of the nearest gauge before you order.
| Metric thickness | Steel | Galvanized | Stainless steel | Aluminum |
|---|---|---|---|---|
| 0.5 mm | 25 ga (0.531 mm) | 27 ga (0.513 mm) | 26 ga (0.478 mm) | 24 ga (0.511 mm) |
| 0.8 mm | 21 ga (0.836 mm) | 23 ga (0.777 mm) | 22 ga (0.795 mm) | 20 ga (0.813 mm) |
| 1 mm | 19 ga (1.062 mm) | 20 ga (1.006 mm) | 20 ga (0.952 mm) | 18 ga (1.024 mm) |
| 1.2 mm | 18 ga (1.214 mm) | 19 ga (1.158 mm) | 18 ga (1.27 mm) | 17 ga (1.151 mm) |
| 1.5 mm | 16 ga (1.519 mm) | 17 ga (1.46 mm) | 17 ga (1.43 mm) | 15 ga (1.45 mm) |
| 2 mm | 14 ga (1.897 mm) | 14 ga (1.994 mm) | 14 ga (1.984 mm) | 12 ga (2.052 mm) |
| 2.5 mm | 12 ga (2.657 mm) | 13 ga (2.372 mm) | 13 ga (2.383 mm) | 10 ga (2.588 mm) |
| 3 mm | 11 ga (3.038 mm) | 11 ga (3.132 mm) | 11 ga (3.175 mm) | 9 ga (2.906 mm) |
| 4 mm | 8 ga (4.176 mm) | 9 ga (3.891 mm) | 9 ga (3.97 mm) | 7 ga (3.665 mm) |
Frequently asked questions
How thick is 16 gauge sheet metal?
It depends on the metal. Sixteen gauge is 0.0598 in (1.52 mm) in carbon steel, 0.0635 in (1.61 mm) galvanized, 0.0625 in (1.59 mm) in stainless steel, and 0.0508 in (1.29 mm) in aluminum. Always name the metal with the gauge.
Is 16 gauge thicker than 18 gauge?
Yes. Gauge runs backwards: the lower the number, the thicker the sheet. Eighteen gauge steel is 0.0478 in, a step thinner than 16 gauge at 0.0598 in. The thickest sheet on this chart, 7 gauge, is about fifteen times thicker than the thinnest, 30 gauge.
Why do the four metals have different gauge tables?
Each system grew up separately. Steel's gauge is based on weight per square foot, galvanized adds a fixed zinc allowance to the steel values, stainless kept a fraction-based series, and aluminum borrowed a geometric wire-gauge formula. No shared standard ever replaced them, so all four are still in daily use.
What gauge is 1.5 mm sheet metal?
Closest matches: 16 gauge in carbon steel (1.519 mm) and galvanized (1.613 mm), between 15 and 16 gauge in stainless (15 gauge is 1.786 mm, 16 gauge is 1.587 mm), and about 14 gauge in aluminum (1.628 mm). The nearest-gauge table on this page covers the common metric sizes.
Can I use a steel gauge chart for aluminum?
No. At 16 gauge the steel value is 0.0598 in and the aluminum value is 0.0508 in — an 18 percent error. The same mistake at 10 gauge is worse in absolute terms: 0.1345 in against 0.1019 in. Use the chart for the metal you are buying.
What is the thickest and thinnest gauge on the chart?
The chart runs from 7 gauge down to 30 gauge. At 7 gauge, stainless is thickest at 0.1875 in and aluminum thinnest at 0.1443 in. At 30 gauge the order flips for galvanized, which at 0.0157 in is thicker than 30 gauge steel at 0.0120 in because the zinc allowance is a larger share of a thin sheet.
Related charts
- Steel gauge chart
- Stainless steel gauge chart
- Aluminum gauge chart
- Galvanized gauge chart
- Gauge to mm converter
- All charts
Thickness values follow Manufacturers' Standard Gauge (ASTM A568) · ASTM A653 (galvanized) · ASTM A480 (stainless) · ASTM B209 (aluminum); cross-checked against published supplier charts, November 2026.