Use this user-friendly roll length calculator tool that calculates the length of the roll easily in a blink of an eye. For that, you need to give the inner diameter, outer diameter, thickness as inputs and then click on the calculate button so that you will get the answers effortlessly.

Roll length can be defined as the length of the material that is in the form of a roll with a given material thickness.

We will look into the formula to find the length of the roll.

**L = (π * ((D ^{2}/4)-(d^{2}/4))) / T**

Where,

D is the outer diameter of the roll.

T is the material thickness.

π is the constant (3.141592654).

L is the length of the roll.

d is the inner diameter.

Now, here we can see the step-by-step procedure to determine the length of the roll manually.

- Initially, write the given values that were given in the problem.
- In the formula, first, we need to find the square of the outer diameter, i.e., π * (Diameter
^{2}/4). - Then, you need to subtract the result with a square of the inner diameter, i.e., π * ((D
^{2}/4)-(d^{2}/4)). - After that, you need to divide the result by material thickness. i.e., (π * ((D
^{2}/4)-(d^{2}/4))) / T. - Finally, you will see the length of the roll.

**Example:**

**Question: **Suppose you have a cylindrical material with an inner diameter of 150nm, an outer thickness of 200nm, and the material is 0.07 thick. Find the length of the cylindrical material?

**Solution:**

Given, d = 150nm

D = 200nm, T = 0.07, L = ?

Apply the formula,

**L = (π * ((D ^{2}/4)-(d^{2}/4))) / T**

Substitute the values in it.

L = ((π * (200^{2} / 4)) - (150^{2} / 4)) / 0.07

= (3.14 * (40000 /4)) - (22500/4)) / 0.07

= (31400 - 5625) / 0.07

= 368214.28 mm.

Therefore the length of the cylindrical material is 368214.28 mm.

More best maths calculators along with the concept are available on the website arithmeticcalculators.com.

**1. What is Roll length?**

The length of the material that has been rolled and in the form of cylindrical with the given material thickness then it is called roll length.

**2. How to find the length of the cylindrical material(Roll)?**

To find the length of the roll we can use the formula, L = (π * ((D^{2}/4)-(d^{2}/4))) / T.

**3. How to use this roll length calculator?**

Just simply give the inner and diameters and the material thickness as inputs and then tap the calculate button you will see the output in seconds.