Tsubo to Square Kilometers (tsubo to km²)

1 tsubo equals 0.000003305785124 square kilometers (rounded).

1 tsubo = 0.000003305785124 square kilometers

How to convert tsubo to square kilometers

To convert tsubo to square kilometers, multiply the number of tsubo by 0.000003305785124. The factor is rounded to 10 significant digits. To go the other way, multiply square kilometers by 302,500.

square kilometers = tsubo × 0.000003305785124

Example: 10 tsubo = 0.00003305785124 square kilometers.

About these units

Tsubo (tsubo)

JapaneseTraditional unit (still used in some regions)

Exactly 400/121 m² (3.3058 m²), one square ken: about two tatami mats. Still the usual unit for land and property prices in Japan.

Walk into a Japanese estate agent's window and the land is still priced per tsubo. The unit is the area of a square ken, which is six shaku on a side, so 36 square shaku. Once the shaku was fixed at 10/33 metre, the tsubo followed as exactly 400/121 square metres, about 3.306.

Builders think of it as two tatami mats, since a mat is half a tsubo, and some sources also count it as 10 go. In farming contexts the same area is sometimes called a bu. A tsubo is a very small plot, so larger land is quoted in multiples such as the se, tan and cho.

The unit travelled with Japanese rule. Korea's pyeong and Taiwan's ping are the same 3.3058 square metres. South Korea formally banned the pyeong in 1961 and made commercial use an offence in 2007, yet it persists informally, much as Japan kept the tsubo after metric units became the legal standard.

1 tsubo = 3.305785124 square meters (approximately).

Sources: Wikipedia: Tsubo; Wikipedia: Japanese units of measurement; Wikipedia: Shaku (unit)

Square Kilometer (km²)

Metric (SI)Current unit

One million square meters (100 hectares). Used for the area of cities, countries and lakes.

Metric land measure took a surprisingly long time to settle on the kilometer. The meter was defined in 1799, yet people initially preferred the myriameter, 10,000 meters, and the French phrase myriamètres par heure was still in print in 1802. The Netherlands adopted the kilometer in 1817 under the name mijl. Once the kilometer was established, the square kilometer followed naturally as the unit for areas too large to count comfortably in hectares or square meters.

One square kilometer is 1,000,000 square meters, or 100 hectares, about 0.3861 square miles or 247.1 acres. A useful picture comes from history: many medieval European cities were enclosed by walls around roughly a square kilometer, with Delft at about 0.9 km² and Lucca at about 1.09 km². A standard 18-hole golf course of 6,000 meters needs about 0.8 km². The symbol km² means the square of a kilometer, not a thousand square meters. The planned Square Kilometre Array radio telescope takes its name from the collecting area it aims for.

1 square kilometer = 1,000,000 square meters (exactly).

Sources: Wikipedia: Square kilometre; Wikipedia: Kilometres per hour

Related conversions

See all area units.