Roll Length Calculator Formula

Roll Length Formula:

\[ \text{Roll Length} = \frac{\pi \times (D^2 - d^2)}{4 \times t} \]

Roll Length:

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1. What is the Roll Length Formula?

The roll length formula calculates the length of material rolled onto a core, given the outer diameter, core diameter, and material thickness. It's commonly used in paper, film, and textile industries.

2. How Does the Calculator Work?

The calculator uses the roll length formula:

\[ \text{Roll Length} = \frac{\pi \times (D^2 - d^2)}{4 \times t} \]

Where:

\( D \) — Outer diameter of the roll (cm)
\( d \) — Core diameter (cm)
\( t \) — Material thickness (mm)
\( \pi \) — Approximately 3.14159

Explanation: The formula calculates the total length by considering the cross-sectional area of the material divided by its thickness.

3. Importance of Roll Length Calculation

Details: Accurate roll length calculation helps in inventory management, production planning, and cost estimation for rolled materials.

4. Using the Calculator

Tips: Enter outer diameter and core diameter in centimeters, and material thickness in millimeters. Ensure outer diameter is larger than core diameter.

5. Frequently Asked Questions (FAQ)

Q1: Why is the thickness in mm while diameters are in cm?
A: This is the industry standard format. The calculator automatically handles the unit conversion.

Q2: Can this be used for any rolled material?
A: Yes, as long as the material has uniform thickness and is tightly wound without gaps.

Q3: What if my core diameter is zero?
A: For materials without a core, use 0 for core diameter. The formula still works.

Q4: How accurate is this calculation?
A: Very accurate for materials with consistent thickness. Compression or loose winding may affect real-world results.

Q5: Can I use inches instead of cm/mm?
A: Yes, but all measurements must be in the same unit system (convert mm to inches if using inches).