Shaku to Millimeters (shaku to mm)

1 shaku equals 303.030303 millimeters (rounded).

1 shaku = 303.030303 millimeters

How to convert shaku to millimeters

To convert shaku to millimeters, multiply the number of shaku by 303.030303. The factor is rounded to 10 significant digits. To go the other way, multiply millimeters by 0.0033.

millimeters = shaku × 303.030303

Example: 10 shaku = 3,030.30303 millimeters.

About these units

Shaku (shaku)

JapaneseTraditional unit (still used in some regions)

The Japanese foot, defined as exactly 10/33 meter (about 30.3 cm). Still the basis of carpentry and building dimensions in Japan.

Shaku is the Japanese reading of the character for chi, the Chinese foot, which began as a hand span from thumb tip to fingertip. Japan adopted the Chinese measuring system around the year 701, and the shaku became its basic length, growing over the centuries to roughly a third of a meter.

Several versions coexisted. The ordinary carpenter's shaku, the kanejaku, was about 30.2 to 30.3 centimeters. A longer kujirajaku, used for cloth and said to have been marked on whale baleen, measured 125/330 meter, near 37.9 centimeters. A longer variant, the korai-shaku, was about 1.17 times the modern value, about 35.5 centimeters.

The Weights and Measures Act of 24 March 1891 ended the variation for the standard unit by defining it as exactly 10/33 meter, about 30.3 centimeters or 11.93 inches. Official use was banned in 1966, yet the shaku still sets building dimensions: a standard three shaku panel is rounded to 910 millimeters.

1 shaku = 0.303030303 meters (approximately).

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

Millimeter (mm)

Metric (SI)Current unit

One thousandth of a meter. Used in engineering, manufacturing and rainfall measurement.

Carl Friedrich Gauss put the millimeter at the base of his 1832 proposal for absolute units, pairing it with the milligram and the second, although the centimeter-based CGS system later won out among scientists. The name combines the metric prefix milli-, from the Latin for one thousand, with the meter. Since 1983 a millimeter has been tied to the speed of light: it is the distance light covers in 1/299,792,458,000 of a second.

Millimeters are the language of fine mechanical work. Standard rulers are divided into them, digital calipers commonly read to 0.01 mm, and mechanical pencil leads come in 0.5 and 0.7 mm. Copy paper is about 0.1 mm thick, and a thin hair, at 0.02 to 0.04 mm across, is close to the smallest thing the naked eye can see. A wave with a frequency of 300 GHz has a wavelength of 1 mm. An inch is exactly 25.4 mm. One trap for readers in the United States is that mil there traditionally means a thousandth of an inch, not a millimeter.

1 millimeter = 0.001 meters (exactly).

Sources: Wikipedia: Millimetre; Wikipedia: Centimetre-gram-second system of units; NIST Guide to the SI, Appendix B.8: conversion factors

Related conversions

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