Coil Weight Calculator
Free calculator for the weight of any metal coil from its outer diameter (OD), inner diameter (ID) and width — for steel, stainless steel, galvanized, aluminium, copper and brass. Enter thickness to also get total strip length. This is an interactive tool; enable JavaScript to use it.
Coil Weight Formula
Weight (kg) = π/4 × (OD² − ID²) × Width × Density × 10⁻⁶ — with OD, ID and Width in millimetres and density in g/cm³. Strip length (m) = Weight ÷ (Thickness × Width × Density × 10⁻³).
Material Densities
| Material | Density (g/cm³) |
|---|---|
| CR Steel (Cold Rolled) | 7.85 |
| HR Steel (Hot Rolled) | 7.85 |
| Galvanized Steel (GI/GP) | 7.85 |
| Stainless Steel 304 | 7.93 |
| Stainless Steel 430 | 7.7 |
| Aluminium | 2.7 |
| Copper | 8.96 |
| Brass | 8.53 |
Frequently Asked Questions
How do you calculate the weight of a steel coil?
Coil weight = π/4 × (OD² − ID²) × width × density × 10⁻⁶, with OD, ID and width in millimetres and density in g/cm³. For steel (7.85 g/cm³), a coil with 1500mm OD, 508mm ID and 1250mm width weighs approximately 15.1 tonnes.
What is the standard inner diameter (ID) of a steel coil?
The most common coil IDs in India are 508mm (20 inch) and 610mm (24 inch). Some cold-rolled and narrow strip coils use 406mm (16 inch).
What density should I use for stainless steel coils?
Use 7.93 g/cm³ for SS 304/316 and about 7.70 g/cm³ for SS 430. Carbon steel (CR, HR, galvanized) is 7.85 g/cm³, aluminium 2.70, copper 8.96 and brass 8.53.
Why does coil weight matter for decoiler selection?
A decoiler must be rated above your heaviest coil with margin — as a rule of thumb, at least 20% above your heaviest regular coil.