Ri (Japanese) to Inches (ri to in)

1 ri (Japanese) equals 154,617.0365 inches (rounded).

1 ri (Japanese) = 154,617.0365 inches

How to convert ri (Japanese) to inches

To convert ri (Japanese) to inches, multiply the number of ri (Japanese) by 154,617.0365. The factor is rounded to 10 significant digits. To go the other way, multiply inches by 0.000006467592593 (rounded).

inches = ri (Japanese) × 154,617.0365

Example: 10 ri (Japanese) = 1,546,170.365 inches.

About these units

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.

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.

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

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

Inch (in)

US & ImperialCurrent unit

1/12 of a foot. Defined as exactly 25.4 millimeters since 1959, when the US and Commonwealth countries agreed a common international inch.

Latin uncia, meaning one-twelfth, is the root of both inch and ounce, and it passed into Old English as ynce. Roman measurers divided their foot into twelve unciae, and the English inch kept that twelfth. After 1066 an inch was reckoned as three barleycorns, and a 1324 statute attributed to Edward II spelled out the definition as three grains of barley, dry and round, placed end to end lengthwise. For centuries the inch was simply a twelfth of a foot, or a thirty-sixth of a yard, and the US and UK each kept their own copy of the standard yard.

Those copies differed slightly until the 1959 international agreement fixed the yard at exactly 0.9144 meter, which made the inch exactly 25.4 millimeters. The US adopted it in 1959 and the UK ratified it in 1963, effective 1964. Today the inch is still the customary unit in the United States and Canada, and the UK keeps it on road signs. Worldwide it also names display diagonals, wheel rims, tire codes and pipe sizes.

1 inch = 0.0254 meters (exactly).

Sources: Wikipedia: Inch; Wikipedia: Yard; NIST Guide to the SI, Appendix B.8: conversion factors

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