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THE FEUTEX TOOLKIT

Quilling Paper Tight Coil Size

Estimate the outer diameter of a tightly rolled paper strip and the strip length needed for a target coil diameter.

Crafts workspace● Runs in your browser
01 Your input
02 Your result
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FormulaEstimated outer diameter = Math.sqrt(core**2+4*length*thickness/Math.PI); Strip length for target diameter = Math.PI*(target**2-core**2)/(4*thickness)

Made for real tasks

  • Estimate the outer diameter of a tightly rolled paper strip and the strip length needed for a target coil diameter.
  • Compare a second measured configuration before cutting materials.
Explore step-by-step workflows →

Worked example

Inputs

Paper strip length
300 mm
Measured paper thickness
0.15 mm
Inside core diameter
2 mm
Target outer diameter
10 mm

Expected results

Estimated outer diameter
7.829162121 mm
Strip length for target diameter
502.6548246 mm

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Measure a representative sample and enter the values in the displayed units.
  2. Calculate the result, mark a test piece and verify it before cutting the final material.

Try this example

{
  "length": 300,
  "thickness": 0.15,
  "core": 2,
  "target": 10
}

Accuracy and scope

Ideal tightly packed spiral approximated by an annulus; gaps, glue and springback enlarge real coils. Loose decorative coils need measured trial results.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.