Tsubo / m² / Tatami Converter

How to Use the Tsubo / Tatami Converter

Enter a value in any one field — tsubo, square metres or tatami mats — and the other fields update automatically. Pick the tatami standard that matches the property when the listing specifies Kyōma, Chūkyō or Edoma.

This helps when reading Japanese real-estate listings, floor plans, rental ads and land prices that mix Western square metres with traditional Japanese area units.

What are tsubo and tatami?

Tsubo (坪) and tatami mats are the traditional units for floor area in Japan. One tsubo is traditionally counted as two tatami mats — about 3.31 m² — though with the Edoma mats this tool uses by default, it works out to about 2.13 mats per tsubo. Even though m² is the legal standard, real-estate listings, floor plans and land prices in Japan are still quoted in tsubo, and room sizes are given as a number of tatami (a "6-jō room"). A tatami mat is not a fixed size, either: it differs by region (Kyōma in western Japan, Edoma around Tokyo). That mix is why a converter helps when you read a Japanese listing and want the area in plain m².

Quick reference

• 1 tsubo ≈ 3.305785 m² ≈ ~2.13 Edoma tatami
• 25 tsubo ≈ 82.64 m² — a typical mid-size apartment
• 6 tatami (Edoma) ≈ 9.29 m² ≈ 2.81 tsubo

When Reading Japanese Listings

Land is often described in tsubo, while room sizes are often described by tatami count. For foreigners buying, renting or comparing properties in Japan, converting both into square metres makes the actual floor area easier to compare across listings.

Limits of Tatami and Property Estimates

Tsubo and square metres have a fixed conversion, but a “tatami” is an estimate whose physical area varies by regional mat standard and building convention. The same six-tatami description therefore produces a different square-metre result when the selected mat size changes. This tool cannot determine whether a property listing uses inside-wall, wall-centre, or measured floor area.

For furniture or renovation work, measure the usable room dimensions and account for columns, storage, wall thickness, and recesses. Use the Area & Volume Calculator for ordinary geometry.

Tsubo, m² and tatami conversion table

One tsubo is exactly 400/121 m² (about 3.3058 m²). The table below converts common tsubo figures into square metres and tatami mats. Tatami come in regional standards, so the same floor area maps to a different number of mats.

From square metres to tsubo

Useful when a Japanese property listing gives m² and you want tsubo. The tatami column uses edoma, the standard most common in Tokyo-area floor plans.

Mat areas used here: kyoma 1.82405 m² (191×95.5 cm), chukyoma 1.6562 m² (182×91 cm), edoma 1.5488 m² (176×88 cm). Mat counts are shown to one decimal place; real floor plans round to whole mats.

FAQ