Tatami Room Size Calculator
Enter an area from a Japanese apartment listing and choose its unit. The converter shows the same planning area in tatami, square meters, tsubo, and square feet while making the statistical assumption visible.
Planning conversion using the Statistics Bureau convention of 1 tatami = 1.65 square meters and 1 tsubo = 3.3 square meters. Physical tatami mats and real-estate advertising conventions can vary by region, building, and listing, so use the property's stated square-meter floor area for contractual decisions.
Enter your scenario
Use the details that match your situation. Your estimate stays in this browser.
How this estimate works
- The selected starting area is converted to square meters as the common base unit.
- Tatami uses 1.65 square meters and tsubo uses 3.3 square meters, matching the government statistical convention that 1 tsubo equals 2 tatami.
- Square feet are derived from square meters using the international foot definition; displayed results are rounded only after conversion.
Official housing and measurement references
- e-Stat housing survey definition: 3.3 m² equals one tsubo or two tatami
- UR Housing: interpreting square-meter and tatami room sizes in Japanese listings
The tatami result is a statistical area convention, not the measured dimensions of a physical mat. Regional mat standards and the area included in a property's advertised floor size can differ.
Frequently asked questions
How many square meters is one tatami in this calculator?
It uses 1.65 square meters per tatami, the statistical convention obtained from 3.3 square meters per tsubo and two tatami per tsubo.
Are all physical tatami mats exactly the same size?
No. Actual mat dimensions vary by regional standard and building. This tool converts area for planning and does not measure a specific mat or room.
Should I rely on tatami count or square meters when renting?
Use the square-meter floor area and the listing's definitions for important comparisons. Tatami count is useful for an intuitive estimate but can reflect a convention rather than physical mats.