Each fibre is about 30 nm and this structure gives an approximate compaction ratio of 40. Then, each nucleosome gives a compaction ratio of 6. If we are considering that there are 6 nucleosomes per 10 nm, then, in those 10 nm we get a compaction ratio of 6×6=36. Considering now that we are taking a fibre into account - 30 nm long - we need to multiply 36 (compaction ratio in 10 nm of a fiber) by 3 (10nm×3=30nm). 36×3=108
The approximate compaction ratio achieved is of 108.