Explanation:

With this calculator you can estimate roughly how long the strings have to be for each color.

Some patterns (like the default one) change the the string positions while an iteration. So the knot count is not only determined by multiplying for each iteration, but has to calculated with the new start position of a string.

Exaclty this does the calculator. The results are shown in the table for each string after the respective iteration of the pattern.

Knotenprobe:

To estimate the length of the strings, you can make a probe part.

Here you have two possibilities.

Then enter the count of iterations of test pattern into the input "Count of knots".
Measure the length of the knotted part and the length difference of the strings and enter these values into the input fields as well.

After these steps, the calculator will estimate the length of strings needed for each string in your desired pattern.