Shakuhachi size guide: Understanding Shaku Lengths
The shaku (尺) or ‘Japanese foot’ is an antiquated unit of length equivalent to 30.3 centimeters, approximately 11.9 inches (a different shaku of 37.9 cm / 14.9 inches is used by traditional Japanese tailors).
The word shakuhachi (尺八) refers to the standardized length of 1.8 shaku. It is an abbreviation of ichi-shaku-hachi-sun or one shaku, eight sun. However, shakuhachi has become the umbrella term used to refer to any length or key. A literal 1.8 shakuhachi is almost always in the key of D4.
Shakuhachi Length and Pitch Discrepancies
Various factors can cause minor or major discrepancies between an instrument length and expected pitch. For this reason, it is often necessary and recommended for shakuhachi craftspeople to provide the precise pitch at room temperature along with the exact length in centimeters.
Common Shakuhachi Lengths and Keys
While these lengths in centimeters are based on a precise 1 shaku = 30.3 cm conversion, actual lengths and pitches can vary slightly due to other dimensions and aspects of their construction. Therefore, this chart provides a general length for a given key.
- 1.6 shaku: 48 cm, Key of E4
- 1.7 shaku: 51 cm, Key of Eb4
- 1.8 shaku: 54 cm, Key of D4
- 1.9 shaku: 57 cm, Key of Db4
- 2.0 shaku: 60 cm, Key of C4
- 2.1 shaku: 63 cm, Key of B3
- 2.2 shaku: 66 cm, Key of Bb3
- 2.4 shaku: 72 cm, Key of A3
- 2.7 shaku: 82 cm, Key of G3
To delve deeper into the nuances of pitch and tuning, please refer to my page Understanding Shakuhachi Pitch and Tuning.

