Diameter Calculator

Diameters, lengths & material thickness calculator for rolls.
Comparison between two rolls.

The Roll Calculator (the app) is suitable for all kinds of materials that are wound onto a roll, e.g. foil, paper, aluminum, laminates, rubber, lawn, PE coatings, etc.

The app has 6 functions:

Comparison calculation: Use the data from a known roll to calculate the new roll length.

Button1: Calculate the new diameter if you already know the length and diameter of a roll.

Button2: Calculate the new roll length if you already know the diameter and length of a roll.

Button3: Calculate the new roll weight or diameter if you already know the weight and diameter of a roll.

The comparison calculation is extremely helpful, but is often overlooked in the app. Use the top 3 buttons!

For example:
The machine is running and the running roll has a diameter of 800mm at 2500m and you want to know what the diameter will be at 5000m, the result shows Ø 1131mm.

Button4: Calculates the diameter if roll length, core diameter and material thickness are known.

Button5: Calculates the roll length if roll diameter, core diameter and material thickness are known.

Button6: Calculates the material thickness when roll length, diameter and core diameter are known.

Note:
The app was developed based on my many years of experience with paper rolls. Please note that it was created using App Inventor. Although this imposes some limitations on optimization, the app is continuously updated. If you find any bugs or want to suggest additional features, don't hesitate to contact me. As I said, use the top 3 buttons (1 to 3) if you know the values from a known role. It is slightly more accurate than the theoretical calculation with the bottom 3 buttons (4 to 6)