rollremain.

ROLLED MATERIAL · ONE CLEAR ESTIMATE

How much
is still wound?

Estimate the length left on a roll from its outside diameter, core diameter and layer thickness. See how a small thickness change affects the answer.

Paper, film + uniform sheetLocal calculationFree, no account
1

Measure the roll

Measure across the roll, through its centre. Use the outside of the core, not its hollow bore. Equal diameters mean no wound material. A core of 0 models an ideal coreless coil.

Enter the thickness of one complete material layer as wound. Include backing or liners when they remain on the roll. The example uses 0.1 mm; it is not a recommended value for your material.

Check thickness sensitivity

The range must contain your nominal thickness. This explores two assumed thicknesses; it is not a measured confidence interval.

WHAT MAKES THIS ESTIMATE USEFUL

Measure both.

The wound material fills the area between two circles. The core’s outside diameter is excluded before estimating length.

Thickness matters.

Length is inversely proportional to thickness. Use the range to see what uncertain thickness does to the result.

Keep it local.

Copy the assumptions or download the figures and cross-section. No account, file upload or contact is needed.