Exceptionally, however, Goichi SAWADA took a different approach of measuring the size of a granary in the Nara period, and found that 1 koku (a unit) then had 2800 cubic sun (寸; a Japanese traditional unit of length).
しかし、澤田吾一は、奈良時代の穀倉の大きさから割り出し、当時の1石として2,800立方寸を得た。