The spiral shape is the most efficient way to arrange objects around a central core. It is frequently found among petals and leaves. Two well known examples of this spiral pattern are sunflower leaves and pinecone scales. Spirals are also the most efficient shape for storing long, thin material while minimising the stress caused by bends and creases. Paper towels, toilet paper, and tape are among the many materials that are stored in spiralling rolls.

Measure the diameter of the plastic piece that the tape is wrapped around. Let the lower case letter "d" represent this diameter in the calculations you will need to do later.

Measure the diameter of the entire roll of tape including the tape itself and the core it is wrapped around. Let this be known as the upper case letter "D".

Calculate the volume of the tape divided by its length with the equation 3.14 / 4 * (D_D - d_d).

Measure the thickness with a ruler if you have one that can measure distances that small. Alternately, most tapes have their thickness printed on the tape, core, or package.

Divide the number you calculated in step 3 by the thickness of the tape. This number is the length of your tape.