Coil Weight Calculator

Quick answer: coil weight = π/4 × (OD² − ID²) × width × density × 10⁻⁶, with dimensions in mm and density in g/cm³. A steel coil with 1500mm OD, 508mm ID and 1250mm width weighs about 15.35 tonnes.

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 and weight per mm of width. A second mode calculates the wound coil OD from strip length or weight - the fastest way to check whether a coil fits a decoiler, recoiler or transport frame. This is an interactive tool; enable JavaScript to use it.

How to Use This Calculator

Pick your material - this sets the density (steel 7.85, SS 304 7.93, aluminium 2.70 g/cm³).
Enter OD, ID and width in millimetres. Common coil IDs are 508mm (20") and 610mm (24").
Add thickness (optional) to also get the total strip length in the coil.
Switch to Coil OD mode to work backwards from length or weight to the wound outer diameter.

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). Coil OD (mm) = √(ID² + 4 × Length × Thickness ÷ π) with length in mm.

Coil Length Calculator

This tool doubles as a coil length calculator: enter OD, ID, width and strip thickness in Weight & Length mode and it returns the total strip length in metres alongside the weight - so you know how many metres a coil holds. Length (m) = Weight (kg) ÷ (Thickness × Width × Density × 10⁻³). Useful when buying or selling coil by the metre (jacketing, cladding, roll-forming) and for estimating run time at a given line speed.

Steel Coil Weight Chart

Approximate weights of common steel coil sizes (density 7.85 g/cm³, 508mm/610mm ID). Use the calculator for exact figures or other materials.

Coil Width	Outer Diameter	Inner Diameter	Approx. Weight
1000 mm	1200 mm	508 mm	7.3 t
1250 mm	1200 mm	508 mm	9.1 t
1250 mm	1500 mm	508 mm	15.4 t
1250 mm	1800 mm	610 mm	22.1 t
1500 mm	1500 mm	508 mm	18.4 t
1500 mm	1800 mm	610 mm	26.5 t
1650 mm	1800 mm	610 mm	29.2 t
2000 mm	1900 mm	610 mm	39.9 t

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).

How do you calculate the outer diameter (OD) of a coil?

OD = √(ID² + 4 × Length × Thickness ÷ π), with ID and thickness in mm and length in mm. Example: 782 m of 2mm strip on a 508mm ID mandrel winds to an OD of about 1500mm - use this to check whether a coil fits a decoiler or recoiler.

How do you calculate coil length from weight?

Length (m) = Weight (kg) ÷ (Thickness × Width × Density × 10⁻³). A 15,350 kg steel coil at 2mm thickness and 1250mm width contains about 782 metres of strip. Enter weight, width and thickness in this coil length calculator to get metres instantly.

How much does a coil of steel weigh?

It depends on size. A common steel coil (1250mm wide, 1500mm OD, 508mm ID) weighs about 15.4 tonnes; a light 1000mm coil at 1200mm OD is around 7.3 tonnes, while a full 2000mm-wide coil at 1900mm OD approaches 40 tonnes. See the steel coil weight chart below or enter exact dimensions.

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.