Kuhanwari（九半割） / Towari（十割） / Tohanwari（十半割）
All of them are the classical methods of calculation for placing Shakuhachi finger-holes. They would be applied when making traditional Shakuhachi. The primary difference between the three is the distance from the bottom of the Shakuhachi to the first finger-hole.
Kuhanwari
20% of the total Shakuhachi length
Towari
22.5% of the total Shakuhachi length
Tohanwari
25% of the total Shakuhachi length
Common rules
・All the gaps between the first and the fourth finger-holes are at equal distances, which is 10% of the total Shakuhachi length.
・The distance between the fourth hole to the fifth hole is 5% of the total Shakuhachi length.
・All the finger-holes are the same sized. They are usually smaller than the ones on the modern Shakuhachi because the traditional style value natural timbre rather than volume or pliability.
However it is very rare to be able to tune Shakuhachi by blindly following these rules. Most of the cases the placement of the finger holes is carefully adjusted.
Kuhanwari
20% of the total Shakuhachi length
Towari
22.5% of the total Shakuhachi length
Tohanwari
25% of the total Shakuhachi length
Common rules
・All the gaps between the first and the fourth finger-holes are at equal distances, which is 10% of the total Shakuhachi length.
・The distance between the fourth hole to the fifth hole is 5% of the total Shakuhachi length.
・All the finger-holes are the same sized. They are usually smaller than the ones on the modern Shakuhachi because the traditional style value natural timbre rather than volume or pliability.
However it is very rare to be able to tune Shakuhachi by blindly following these rules. Most of the cases the placement of the finger holes is carefully adjusted.