We use a scale length of 65 centimetres as standard. But many people prefer different size scales. Tall people with longer arms and larger hands, for instance, may opt for scale sizes of 66 centimetres and adolescents still growing and many women with smaller hands may prefer shorter string lengths of, for example, 63 centimetres.
Shorter scale lengths simplify fingering across several positions. But shorter scales also reduce the space between the frets that is available for more complex fingering positions.
The table of theoretical scale sizes lists the precise dimensions for the individual spaces between frets.