$1911

I didn't cut strings according to the formula right away, just measured what I used and compared that to the outcome of the formula:-)

One thing you need to be careful of with this formula is that the definition of a "repeating pattern" that this site uses requires that the beginning and ending COLORS match, not that each string returns to the same place.
For example with pattern #6025 there are 3 strings on each side that use color B.
The first string is not used in any of it's 4 knots and returns to the same position.
The second string is used in 4 knots and not used in 2.
The third string is not used in any of its 6 knots.
You would think that the second string needs to be longer than the third string, except that after one repetition of the pattern, the second and third strings switch places. So actually both of these strings need to be about the same length!

@EdBlair, that's an interesting point. I guess what you would have to do if you wanted the formula to work would be to add more rows so that the string returns to the same spot.

Is there a video about this because I still don't get it.

What I would really like to see is a number at the bottom of each string that indicates how many times it is used for a knot. Then we would easily be able to tweak the pattern for optimal use of all strings and decide on their length.

A suggestion also... if you're making a bracelet, and that design significantly hogs a particular thread or color up more than the rest, maybe posting a warning for future users about it in the pattern comments might be a good idea... to benefit from the previous experiences.

for my part here is my method that looks a little like yours.
I also count the number of times the thread is used. I also look at whether this thread returns to its place at the end of the repetition or not and then I calculate in relation to the number of ranks that I need.
as an example for the bracelet 86055
At 7 knots for 24 rows and returns to A
B 8 B
C 6 C
D 10 D1
E 13 E
F 14 F
G 15 G
A1(second A) 18 A2
A2 17 A1
G1 15 G1
F1 14 F1
E1 13 E1
D1 9 D
C1 6 C1
B1 8 B1
A3 7 A3
419/5000
as I use an average of 95 to 100 rows for a bracelet, I have multiplied by 4 the number of knots of each thread and then I add 30 cm to this number for the final length of each thread.voila my results
A 28 for 96 rows then 58 cm by adding 30 cm to 28
A3 being the same color and the same length it gives me AA3 116 cm BB1 124 CC1 108
DD1 136 EE1 164 FF1 172 GG1 180 A1A2 200

I know this is 4 years after this was posted but I have some questions.

For K does it mean a knot that you made with that strand or does it include if it was the base for another knot to go on?

And for N does it mean all the knots made without the specified strand in the pattern, all the knots not made by the specified strand in the pattern, or all the knots made onto the specified strand?

Sorry... I'm not v good at this

K is a knot with the thread, N is the thread inside another knot.

thank you! I figured it made the most sense like that but 100% don't trust myself so thought I'd ask.