Ri (Japanese) to Meters (ri to m)

1 ri (Japanese) equals 3,927.272727 meters (rounded).

1 ri (Japanese) = 3,927.272727 meters

How to convert ri (Japanese) to meters

To convert ri (Japanese) to meters, multiply the number of ri (Japanese) by 3,927.272727. The factor is rounded to 10 significant digits. To go the other way, multiply meters by 0.0002546296296 (rounded).

meters = ri (Japanese) × 3,927.272727

Example: 10 ri (Japanese) = 39,272.72727 meters.

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)

Meter (m)

Metric (SI)Current unit

The SI base unit of length. Since 1983 it is defined as the distance light travels in a vacuum in 1/299,792,458 of a second.

Meter comes from the Greek metron, a measure. In 1791 the French National Assembly defined it as one ten-millionth of the distance from the equator to the North Pole along a great circle through Paris, after rejecting the length of a seconds pendulum because that length changes with local gravity. The surveyors Delambre and Méchain measured the meridian arc, and in 1799 a platinum bar known as the Mètre des Archives became the physical standard. NIST notes that this Earth-based meter turned out to be about 0.2 mm shorter than the true pole-to-equator fraction it was meant to represent.

The 1875 Treaty of the Meter created the CGPM and the BIPM to look after common standards, and in 1889 a platinum-iridium prototype bar took over; the original is still kept at the BIPM. In 1960 the meter was tied to 1,650,763.73 wavelengths of an orange-red krypton-86 line, and in 1983 to the speed of light, which made length a quantity derived from the time standard. The 2018 revision reworded that definition without changing the meter's size. NIST offers a handy yardstick for scale: a pace, meaning two steps, is roughly a meter or a yard.

The meter is the reference unit for length on this site.

Sources: BIPM: history of the metre; NIST: the meter and the SI redefinition; Wikipedia: Metre

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