Sheet buyers often talk in gauge, while mills and drawings use millimetres. Use this chart to convert between the two and to estimate weight before you order.
Gauge to mm (SWG)
In India, sheet "gauge" usually follows the Standard Wire Gauge (SWG). A higher gauge number means a thinner sheet. Weights are theoretical, at a steel density of 7.85 g/cm³, for a standard 1250 × 2500 mm sheet.
| Gauge | Thickness (mm) | Weight (kg/m²) | Sheet 1250×2500 (kg) |
|---|---|---|---|
| 30 G | 0.32 | 2.47 | 7.7 |
| 28 G | 0.38 | 2.95 | 9.2 |
| 26 G | 0.46 | 3.59 | 11.2 |
| 24 G | 0.56 | 4.39 | 13.7 |
| 22 G | 0.71 | 5.58 | 17.4 |
| 20 G | 0.91 | 7.17 | 22.4 |
| 18 G | 1.22 | 9.57 | 29.9 |
| 16 G | 1.63 | 12.76 | 39.9 |
| 14 G | 2.03 | 15.95 | 49.8 |
| 12 G | 2.64 | 20.74 | 64.8 |
| 10 G | 3.25 | 25.52 | 79.8 |
Common thicknesses in mm
| Thickness (mm) | Weight (kg/m²) | Sheet 1250×2500 (kg) | Plate 1500×6300 (kg) |
|---|---|---|---|
| 0.5 | 3.92 | 12.3 | 37 |
| 0.63 | 4.95 | 15.5 | 47 |
| 0.8 | 6.28 | 19.6 | 59 |
| 1 | 7.85 | 24.5 | 74 |
| 1.2 | 9.42 | 29.4 | 89 |
| 1.5 | 11.77 | 36.8 | 111 |
| 1.6 | 12.56 | 39.2 | 119 |
| 2 | 15.70 | 49.1 | 148 |
| 2.5 | 19.62 | 61.3 | 185 |
| 3 | 23.55 | 73.6 | 223 |
| 4 | 31.40 | 98.1 | 297 |
| 5 | 39.25 | 122.7 | 371 |
| 6 | 47.10 | 147.2 | 445 |
| 8 | 62.80 | 196.2 | 593 |
| 10 | 78.50 | 245.3 | 742 |
| 12 | 94.20 | 294.4 | 890 |
| 16 | 125.60 | 392.5 | 1187 |
| 20 | 157.00 | 490.6 | 1484 |
| 25 | 196.25 | 613.3 | 1855 |
Calculate the weight yourself
Weight (kg) = Length (m) × Width (m) × Thickness (mm) × 7.85
Example: one CR sheet of 1.2 mm in 1250 × 2500 mm weighs 1.25 × 2.5 × 1.2 × 7.85 = about 29.4 kg. Fifty such sheets are about 1.47 tonnes.
Things to keep in mind
- Actual weight can differ slightly from theoretical weight because of mill thickness tolerance. Billing is usually on actual weight.
- Galvanised (GP) sheets weigh a little more than the base steel because of the zinc coating.
- Always confirm thickness in mm on your order. Gauge names can mean different things to different suppliers.