What it is
Japanese wasai shaku is 1 shaku = 10 sun = 10/33 m ≈ 30.303 cm ≈ 11.930 in. Not Chinese chi (1/3 m ≈ 13.123 in), not ligne.
How to use
shaku × 11.930 = inches (exact: (10/33) / 0.0254). 1 shaku ≈ 11.930 in. 1 shaku = 10 sun.
in = 尺 × 11.93032689
Example: 1 尺 = 11.93032689 in
Common uses
Kimono length, fabric cuts, wasai vs inch. 1 shaku = 10 sun.
Conversion tips
1 wasai shaku ≈ 11.93 in; 1 Chinese chi ≈ 13.12 in. Write wasai shaku so it is not confused with chi.