← Back to Bead BoardSheet metal gauge chart
Gauge numbers mean different thicknesses for different metals. 16 gauge steel is 0.0598". 16 gauge stainless is 0.0625". 16 gauge aluminum is 0.0508". This chart has all four standards side by side so you stop guessing.
Gauge to thickness — inches
Steel uses the Manufacturer's Standard Gauge (MSG). Stainless steel uses its own fractional-inch standard. Aluminum uses Brown & Sharpe (same as AWG). Galvanized adds zinc coating thickness to MSG.
Sources: Manufacturer's Standard Gauge (ASTM), Brown & Sharpe / AWG for aluminum. Galvanized includes zinc coating on both sides. Stainless uses the traditional fractional-inch-based gauge standard used by most suppliers and fabricators.
Gauge to thickness — millimeters
Need the weight, not just the thickness?
This chart gives you the thickness. To get the weight of a specific piece, use the calculator for your material:
Questions welders keep asking
Why does the same gauge number mean different thicknesses for different metals?
Because each metal uses a different gauge standard. Carbon steel uses the Manufacturer's Standard Gauge (MSG), which was defined by weight per square foot over a century ago. Stainless steel uses its own standard based on fractional-inch increments. Aluminum uses the Brown & Sharpe gauge (same as American Wire Gauge). Galvanized steel uses the MSG system but adds thickness for the zinc coating. The takeaway: always specify the metal when calling out a gauge.
What gauge is 1/8 inch steel?
11 gauge is the closest. 11 gauge steel is 0.1196 inches, which is about 4% thinner than a true 1/8" (0.125). If you need exactly 1/8" thick steel, call out the thickness in inches or millimeters on the order — not the gauge number.
What is the most common gauge for sheet metal fabrication?
16 gauge and 18 gauge are the workhorses. 16 gauge steel (0.0598") is thick enough for structural brackets, enclosures, and equipment panels. 18 gauge (0.0478") is the standard for ductwork, light enclosures, and decorative metalwork. Thinner than 20 gauge is mostly for flashing, trim, and non-structural applications.
Is 14 gauge stainless thicker than 14 gauge steel?
Yes. 14 gauge stainless is 0.0781" (5/64") while 14 gauge steel is 0.0747". That is about 4.5% thicker. This catches people off guard when they switch between materials. The stainless gauge standard uses fractional-inch-based values, while the steel MSG standard was derived from weight per square foot.
How do you convert gauge to weight per square foot?
Look up the thickness in inches from the chart, then multiply by the density constant: 40.84 for mild steel, 41.62 for 304 stainless, 14.04 for 6061 aluminum. Example: 16 gauge steel = 0.0598" × 40.84 = 2.44 lb/ft². The historical MSG system used a constant of 41.82, which is why some older charts show slightly different weight values.