Square Meters to Tan (m² to tan)

1 square meter equals 0.001008333333 tan (rounded).

1 square meter = 0.001008333333 tan

How to convert square meters to tan

To convert square meters to tan, multiply the number of square meters by 0.001008333333. The factor is rounded to 10 significant digits. To go the other way, multiply tan by 991.7355372 (rounded).

tan = square meters × 0.001008333333

Example: 10 square meters = 0.01008333333 tan.

About these units

Square Meter (m²)

Metric (SI)Current unit

The SI unit of area: a square one meter on each side. Used for floor areas and property sizes in most of the world.

Squaring the meter was built into the metric system from the start. The French law of 18 Germinal, Year III (7 April 1795) defined the are, the land unit that gave the hectare its name, as exactly 100 square meters, so the square meter was already the foundation of metric land measure. Nobody is credited with inventing it as a separate unit. It is simply the area of a square one meter on each side, and any SI prefix that works for the meter works for it, with the prefix squared along with the unit.

That squaring catches people out: a square kilometer is one million square meters, not one thousand. Since 1983 the meter has been defined through the speed of light, so the square meter is tied to a constant of nature as well as to the second. A hectare, about the area of Trafalgar Square in London, is 10,000 square meters. In everyday terms one square meter is about 10.76 square feet. Unicode has a compatibility character for it, but the recommended way to write it is the plain superscript two: m².

The square meter is the reference unit for area on this site.

Sources: Wikipedia: Square metre; Wikipedia: Are (unit); NIST: the meter and the SI redefinition

Tan (tan)

JapaneseTraditional unit (still used in some regions)

300 tsubo (about 991.74 m²), about a quarter of an acre. A traditional measure of farmland.

Rice paddies were counted in tan. One tan is 300 tsubo, or exactly 120,000/121 square metres, about 991.7, which is slightly less than a quarter of an acre. It equals ten se, and ten tan make a cho, so a farmer with several tan had a modest holding by the standards of the tax registers.

The unit belongs to the same system that valued land in koku of rice. Under the Tokugawa shogunate the kokudaka assessed a plot by its yield, and surveyed land was recorded in these agricultural areas. A common claim that one tan was the area needed to grow one koku is not confirmed by the sources consulted, so it should be taken as a rough tradition.

Japan signed the Metre Convention in 1885 and the 1891 weights and measures law gave the traditional units fixed metric equivalents. The Measurements Law of 1951 moved the country to metric units from 1959, and the tan survives mainly in rural land transactions and in talk of rice farming.

1 tan = 991.7355372 square meters (approximately).

Sources: Wikipedia: Japanese units of measurement; Wikipedia: Kokudaka; Wikipedia: Koku

Related conversions

See all area units.