Kilograms to Monme (kg to mon)

1 kilogram equals 266.6666667 monme (rounded).

1 kilogram = 266.6666667 monme

How to convert kilograms to monme

To convert kilograms to monme, multiply the number of kilograms by 266.6666667. The factor is rounded to 10 significant digits. To go the other way, multiply monme by 0.00375.

monme = kilograms × 266.6666667

Example: 10 kilograms = 2,666.666667 monme.

About these units

Kilogram (kg)

Metric (SI)Current unit

The SI base unit of mass. Since 2019 it is defined by fixing the value of the Planck constant, replacing the old platinum-iridium cylinder in Paris.

Oddly for a base unit, the kilogram began life as a derived one. In 1793 revolutionary France defined the grave as the mass of one litre of water, and a decree of 1795 then replaced it with the kilogramme, a name built from the Greek khilioi (a thousand) and gramma, a Late Latin word for a small weight. In 1799 a platinum cylinder, the Kilogramme des Archives, became the physical standard, matching a cubic decimetre of water at its densest, around 4 degrees Celsius. In 1889 the metric community adopted a platinum-iridium cylinder made in 1879, the International Prototype of the Kilogram, nicknamed Le Grand K.

The kilogram is still the only SI base unit with a prefix in its name. Because SI forbids stacked prefixes, a millionth of a kilogram is a milligram rather than a microkilogram, so every mass prefix is attached to the gram. Calibrating every national standard against one object in a vault near Paris meant that all of them drifted relative to it, so in November 2018 member states voted to tie the kilogram to a fixed value of the Planck constant. The change took effect on 20 May 2019. Day to day nothing shifted, but the definition no longer depends on a single piece of metal.

The kilogram is the reference unit for weight & mass on this site.

Sources: NIST: Kilogram introduction (SI redefinition); Wikipedia: Kilogram

Monme (mon)

JapaneseTraditional unit (still used in some regions)

Exactly 3.75 g. A Japanese unit still used for pearls (where it is called momme) and for the weight of silk.

Monme takes its name from the weight of a single mon, the small copper coin of old Japan, so the word amounts to "mon weight". Edo-period merchants weighed silver in monme rather than counting it, and prices were quoted in silver monme until that system was abolished in 1868.

The Weights and Measures Act of 1891 fixed the monme at one thousandth of a kan, which is exactly 3.75 g, the figure used here. A modern Japanese 5 yen coin is often cited as weighing about one monme. Today the unit survives mainly in the pearl trade, where the spelling momme is common internationally and loose pearls and strands are weighed in it.

Silk is different: the textile momme is a separate convention of pounds per piece of cloth 45 inches wide and 100 yards long, so it should not be converted as a mass.

1 monme = 0.00375 kilograms (exactly).

Sources: Wikipedia: Japanese units of measurement; Japanese Wikipedia: Monme; Wikipedia: Pearl; Wikipedia: Units of textile measurement

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