🌾 Tan Area Converter (反 to m2)

The Tan Area Converter converts between tan (反) and modern area units. The tan is a traditional Japanese land area unit, primarily used for agricultural fields, equal to 300 bu (歩, same as tsubo) or approximately 991.74 m2.

The tan is approximately 10 are (1 decare), making it very close to the European "decare" unit. In rice farming, 1 tan of paddy yields about 300-500 kg of polished rice (varies by variety and year).

Conversion formula:

Key conversions:

• 1 tan = 991.74 m2 = 0.9917 hectares
• 1 tan = 300 tsubo (坪)
• 1 tan = 0.2451 acres
• 1 tan = 10 are (precisely, since 1 are = 100 m2, so 1 tan = ~10 are)

The system is fully decimal for agricultural land: 1 cho = 10 tan, 1 tan = 10 se (畝), 1 se = 30 bu.

For larger agricultural plots, use our cho (1 hectare) converter. For real estate measurements, try the tsubo converter. General area conversions are available in the area converter.

1. Enter the area in tan (e.g. 5 for a mid-size rice field).
2. Select the target unit.
3. Click Convert to see the result.
4. Refer to the agricultural unit table.

How many m2 is one tan?

One tan equals 991.74 m2 (exactly 120000/121 m2, derived from 300 x 400/121). This is very close to 1000 m2 (10 are), and the two are often treated as equivalent in practice.

How much rice does 1 tan produce?

One tan of rice paddy yields approximately 300-500 kg of polished rice per harvest, depending on variety, weather, and farming technique. This is enough to feed 1-2 people for a year.

What is the difference between tan and cho?

1 cho (町) = 10 tan (反). The cho is the larger unit, approximately 1 hectare (9917 m2). Tan and cho are both primarily used for agricultural land measurement.

Is tan still used in Japan?

The tan is no longer used for new legal documents (m2 is standard), but it persists in agricultural contexts: land registries, farmer conversations, and rice yield calculations. Older land parcels are often still described in tan and cho.

How does tan compare to acres?

One tan (991.74 m2) equals about 0.245 acres, or roughly 1/4 of an acre. A 10-tan field (1 cho) is about 2.45 acres, comparable to a small American farm field.

Rice yield per tan. One tan of rice paddy produces approximately 300-500 kg of polished rice, or about 5-8 bales (kome-dawara). This is roughly enough rice to feed 1-2 people for a year.

The tan vs are vs decare. The tan (991.74 m2) is almost identical to 10 are (1000 m2) or 1 decare. The slight difference (0.83%) comes from the traditional definition based on tsubo. In practice, many Japanese farmers round 1 tan to ~1000 m2.

Land registration. Japanese agricultural land registers (tochi daicho) still reference tan and cho for older parcels, even though official measurements are in m2. A "5-tan field" is immediately understood by farmers.

The se (畝). The se (1/10 tan = 99.17 m2) is used for smaller field sections. Vegetable garden sizes are often described in se. 1 se is roughly the size of a small backyard garden plot.