Gauge chart
18 gauge steel thickness
18 gauge steel is 0.0478 inches thick, which is 1.21 mm. One square foot weighs 1.95 pounds.
18 gauge in figures
Inches 0.0478in
Millimetres 1.21mm
Weight 1.95lb/ft²
4×8 sheet 62lb
Close to 3/64 inch (0.0469). In practice, about three sixty-fourths of an inch.
| Material | Inches | mm | lb/ft² | Standard |
|---|---|---|---|---|
| Steel | 0.0478 | 1.21 | 1.95 | Manufacturers' Standard Gauge (MSG) |
| Galvanized | 0.0516 | 1.31 | 2.11 | MSG plus G90 zinc coating |
| Stainless | 0.0500 | 1.27 | 2.08 | Manufacturers' standard for stainless sheet |
| Aluminium | 0.0403 | 1.02 | 0.57 | Brown & Sharpe (AWG) |
What 18 gauge steel is used for
Light enclosures, ductwork, automotive body panels, kick plates and appliance skins.
Common questions
How thick is 18 gauge steel?
- 18 gauge steel is 0.0478 inches thick, which is 1.21 mm. One square foot weighs 1.95 pounds. For reference that is about three sixty-fourths of an inch. Thicknesses are nominal and mill tolerance applies, so measure the sheet for anything structural.
What is 18 gauge steel in mm?
- 1.21 mm. The conversion is exact: 0.0478 inches times 25.4 gives 1.214 mm, rounded to 1.21.
Is 18 gauge stainless the same thickness as 18 gauge steel?
- No. 18 gauge galvanized is 0.0516 inches, stainless is 0.0500 inches, aluminium is 0.0403 inches, against 0.0478 inches for uncoated steel. Each material is tabulated under a different standard, so the gauge number alone does not give a thickness.
What does a 4x8 sheet of 18 gauge steel weigh?
- About 62 pounds. A 4 foot by 8 foot sheet is 32 square feet and 18 gauge weighs 1.95 pounds per square foot, so 32 times 1.95 is 62.5 pounds.