Ri (Japanese) (ri)

JapaneseTraditional unit (still used in some regions)

36 chō, about 3.927 km. The traditional Japanese 'mile', roughly an hour's walk.

1 ri (Japanese) = 3,927.272727 meters (approximately).

About the ri (Japanese)

Ri comes from the Chinese li, written with characters said to combine field and earth, hinting at the span of a village. China's li has varied widely, from about 323 meters under the Tang to exactly 500 meters in the modern standard, so a bare reference to a ri is ambiguous without context.

Early Japanese practice used a ri of six cho, around 500 to 600 meters. Later it came to mean the distance a loaded porter could cover on a mountain road in an hour, which gave versions of 36, 40 and 48 cho. The Tokugawa shogunate fixed 36 cho, and the 1891 law adopted that count as 216/55 kilometer, about 3.927 kilometers or 2.44 miles.

Modern distances use kilometers, leaving the ri in proverbs and literature, where it suggests roughly an hour's walk. Because the length changed over time and by region, a distance quoted in ri from an old text should not be converted without knowing which ri was meant.

Sources: Wikipedia: Ri (unit); Wikipedia: Japanese units of measurement; Japanese Wikipedia: Shakkanho (尺貫法)

Ri (Japanese) conversion chart

1 ri (Japanese) expressed in every other length unit:

More Japanese units

• sun (length)
• shaku (length)
• ken (length)
• jō (length)
• chō (length)
• monme (weight & mass)
• kin (weight & mass)
• kan (weight & mass)
• gō (volume)
• shō (volume)
• tō (volume)
• koku (volume)
• jō (tatami mat) (area)
• tsubo (area)
• se (area)
• tan (area)

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