Reference & Charts
Sheet Metal Gauge Chart
A searchable sheet-metal gauge chart. Gauge is material-specific — the same number is a different thickness in steel, stainless, aluminum, and galvanized — so pick the material and read the real thickness in inches and millimetres. Filter by material or search a gauge (e.g. 16).
71 entries · Last verified: 2026-07-17
Sheet-metal gauge is an old numbering system where a higher gauge number means a thinner sheet — and, crucially, the same number means a different thickness depending on the material. 16-gauge steel is 0.0598", but 16-gauge aluminum is about 0.051" and 16-gauge stainless is 0.0625". Pick the material below and read the real thickness; don't rely on a single all-material chart.
These are nominal reference thicknesses. Real sheet ships with a mill tolerance, so for fit-critical work cut to the measured or certified thickness rather than the nominal gauge. Aluminum here is the Brown & Sharpe (AWG) series computed from its defining formula; steel is the Manufacturers' Standard Gauge; stainless and galvanized use their own standard tables.
Showing 71 of 71
| Gauge | Material | Thickness(in) | Thickness(mm) |
|---|---|---|---|
| 7 ga | Steel (uncoated) | 0.1793 in | 4.55 mm |
| 8 ga | Steel (uncoated) | 0.1644 in | 4.18 mm |
| 9 ga | Steel (uncoated) | 0.1495 in | 3.8 mm |
| 10 ga | Steel (uncoated) | 0.1345 in | 3.42 mm |
| 11 ga | Steel (uncoated) | 0.1196 in | 3.04 mm |
| 12 ga | Steel (uncoated) | 0.1046 in | 2.66 mm |
| 13 ga | Steel (uncoated) | 0.0897 in | 2.28 mm |
| 14 ga | Steel (uncoated) | 0.0747 in | 1.9 mm |
| 15 ga | Steel (uncoated) | 0.0673 in | 1.71 mm |
| 16 ga | Steel (uncoated) | 0.0598 in | 1.52 mm |
| 17 ga | Steel (uncoated) | 0.0538 in | 1.37 mm |
| 18 ga | Steel (uncoated) | 0.0478 in | 1.21 mm |
| 19 ga | Steel (uncoated) | 0.0418 in | 1.06 mm |
| 20 ga | Steel (uncoated) | 0.0359 in | 0.91 mm |
| 21 ga | Steel (uncoated) | 0.0329 in | 0.84 mm |
| 22 ga | Steel (uncoated) | 0.0299 in | 0.76 mm |
| 23 ga | Steel (uncoated) | 0.0269 in | 0.68 mm |
| 24 ga | Steel (uncoated) | 0.0239 in | 0.61 mm |
| 7 ga | Stainless | 0.1875 in | 4.76 mm |
| 8 ga | Stainless | 0.1719 in | 4.37 mm |
| 9 ga | Stainless | 0.1563 in | 3.97 mm |
| 10 ga | Stainless | 0.1406 in | 3.57 mm |
| 11 ga | Stainless | 0.125 in | 3.18 mm |
| 12 ga | Stainless | 0.1094 in | 2.78 mm |
| 13 ga | Stainless | 0.0938 in | 2.38 mm |
| 14 ga | Stainless | 0.0781 in | 1.98 mm |
| 15 ga | Stainless | 0.0703 in | 1.79 mm |
| 16 ga | Stainless | 0.0625 in | 1.59 mm |
| 17 ga | Stainless | 0.0563 in | 1.43 mm |
| 18 ga | Stainless | 0.05 in | 1.27 mm |
| 19 ga | Stainless | 0.0438 in | 1.11 mm |
| 20 ga | Stainless | 0.0375 in | 0.95 mm |
| 21 ga | Stainless | 0.0344 in | 0.87 mm |
| 22 ga | Stainless | 0.0313 in | 0.8 mm |
| 23 ga | Stainless | 0.0281 in | 0.71 mm |
| 24 ga | Stainless | 0.025 in | 0.64 mm |
| 7 ga | Aluminum | 0.1443 in | 3.67 mm |
| 8 ga | Aluminum | 0.1285 in | 3.26 mm |
| 9 ga | Aluminum | 0.1144 in | 2.91 mm |
| 10 ga | Aluminum | 0.1019 in | 2.59 mm |
| 11 ga | Aluminum | 0.0907 in | 2.3 mm |
| 12 ga | Aluminum | 0.0808 in | 2.05 mm |
| 13 ga | Aluminum | 0.072 in | 1.83 mm |
| 14 ga | Aluminum | 0.0641 in | 1.63 mm |
| 15 ga | Aluminum | 0.0571 in | 1.45 mm |
| 16 ga | Aluminum | 0.0508 in | 1.29 mm |
| 17 ga | Aluminum | 0.0453 in | 1.15 mm |
| 18 ga | Aluminum | 0.0403 in | 1.02 mm |
| 19 ga | Aluminum | 0.0359 in | 0.91 mm |
| 20 ga | Aluminum | 0.032 in | 0.81 mm |
| 21 ga | Aluminum | 0.0285 in | 0.72 mm |
| 22 ga | Aluminum | 0.0253 in | 0.64 mm |
| 23 ga | Aluminum | 0.0226 in | 0.57 mm |
| 24 ga | Aluminum | 0.0201 in | 0.51 mm |
| 8 ga | Galvanized steel | 0.1681 in | 4.27 mm |
| 9 ga | Galvanized steel | 0.1532 in | 3.89 mm |
| 10 ga | Galvanized steel | 0.1382 in | 3.51 mm |
| 11 ga | Galvanized steel | 0.1233 in | 3.13 mm |
| 12 ga | Galvanized steel | 0.1084 in | 2.75 mm |
| 13 ga | Galvanized steel | 0.0934 in | 2.37 mm |
| 14 ga | Galvanized steel | 0.0785 in | 1.99 mm |
| 15 ga | Galvanized steel | 0.071 in | 1.8 mm |
| 16 ga | Galvanized steel | 0.0635 in | 1.61 mm |
| 17 ga | Galvanized steel | 0.0575 in | 1.46 mm |
| 18 ga | Galvanized steel | 0.0516 in | 1.31 mm |
| 19 ga | Galvanized steel | 0.0456 in | 1.16 mm |
| 20 ga | Galvanized steel | 0.0396 in | 1.01 mm |
| 21 ga | Galvanized steel | 0.0366 in | 0.93 mm |
| 22 ga | Galvanized steel | 0.0336 in | 0.85 mm |
| 23 ga | Galvanized steel | 0.0306 in | 0.78 mm |
| 24 ga | Galvanized steel | 0.0276 in | 0.7 mm |
Frequently asked
- Why is 16-gauge a different thickness in steel vs aluminum?
- Because gauge is a material-specific legacy system, not a unit. Steel uses the Manufacturers' Standard Gauge (16 ga = 0.0598"), while aluminum uses the Brown & Sharpe / AWG series (16 ga ≈ 0.051"). Always state the material with the gauge, or better, give the thickness in inches or millimetres.
- Is the actual sheet exactly this thick?
- It's the nominal value. Rolled sheet carries a thickness tolerance that varies by material, gauge, and standard, so for tight tolerances measure the actual stock or work from the mill certificate — don't assume the nominal gauge thickness.
- How do I convert gauge to millimetres?
- Find the inch thickness for your material and gauge, then multiply by 25.4. This chart lists both so you don't have to — e.g. 14-gauge steel is 0.0747" = 1.90 mm.
Sources
- Manufacturers' Standard Gauge for uncoated hot- and cold-rolled steel sheet
- Standard gauge tables for stainless steel and galvanized steel sheet
- Brown & Sharpe (American Wire Gauge) series for aluminum — thickness = 0.005 × 92^((36 − n)/39) in
- Thickness is nominal; mill tolerances apply per the applicable ASTM specification