Aluminum coils are widely used in various industries, including construction, automotive, and aerospace. Knowing the length of an aluminum coil is essential for production planning and inventory management. In this blog post, we will discuss two methods to calculate the length of an aluminum coil: you can easily calculate the length of an aluminum coil from its inner and outer diameters, thickness, weight, width, and density.

Schematic diagram of aluminum coil specification parameters

## Method 1: From Inner Diameter, Outer Diameter, and Thickness

To calculate the length of an aluminum coil using its inner diameter, outer diameter, and thickness, you can use the following formula:

**L = [3.14/4 x (OD^2 - ID^2)] / (T x 1000)**

where L is the length of the coil in meters, OD is the outer diameter of the coil in millimeters, ID is the inner diameter of the coil in millimeters, and T is the thickness of the aluminum in millimeters, the coefficient 1000 is used to compensate the dimensions in [mm] with the length in [m].

The derivation process of this formula is as follows:

First, we need to calculate the volume of the coil in cubic millimeters:

V = [3.14/4 x (OD^2 - ID^2)] x W

Next, we need to convert the volume to length by dividing it by the section of the coil determined by coil width and thickness:

L = V / (W x T x 1000)

where W is the width of the aluminum coil in millimeters.It’s easy to see that the width of the coil is not needed, so the final formula becomes:

L = [3.14/4 x (OD^2 - ID^2)] / (T x 1000)

For example, let's say we have an aluminum coil with an outer diameter of 1500mm, an inner diameter of 406mm, and a thickness of 2mm. We can calculate the length of the coil as follows:

L = [3.14/4 x (1500^2 - 406^2)] / (2 x 1000) = 3273.7 meters

aluminum coil from huawei aluminum

## Method 2: From Weight, Width, and Thickness

If you do not have information about the weight or material type of the aluminum coil, you can calculate the length of the coil using its weight, width, and thickness. The formula for this method is:

**L = (Weight / (W x T x D)) x 10^6**

where L is the length of the coil in meters, Weight is the weight of the aluminum coil in kilograms, W is the width of the coil in millimeters, T is the thickness of the aluminum in millimeters, and D is the density of the aluminum in kilograms per cubic meter, the 1000 coefficient is used in this case to compensate for the dimensions of Volume in [mm^3] and Length in [m].

For example, let's say we have an aluminum coil with a weight of 1000kg, a width of 1000mm, a thickness of 1mm, and a density of 2700kg/m3. We can calculate the length of the coil as follows:

L = (1000 / (1000 x 1 x 2700)) x 10^6 = 370 meters.