A tatami mat (1 jō, 畳) is a long 1:2 rectangle. See one mat’s dimensions and area, plus the regional sizes — and convert any number of mats to square feet or square meters.
1 jō = 17.4375 sq ft (1.62 m²) / 1 sq ft = 0.0573476 jō
| jō | sq ft | m² |
|---|---|---|
| 1 | 17.4375 | 1.62 |
| 2 | 34.8751 | 3.24 |
| 4.5 | 78.4689 | 7.29 |
| 6 | 104.625 | 9.72 |
| 8 | 139.5 | 12.96 |
| 10 | 174.375 | 16.2 |
| 12 | 209.25 | 19.44 |
| sq ft | jō |
|---|---|
| 10 | 0.573476 |
| 20 | 1.14695 |
| 30 | 1.72043 |
| 50 | 2.86738 |
| 100 | 5.73476 |
| 150 | 8.60213 |
| 200 | 11.4695 |
Chart values are rounded to 6 significant figures.
A tatami is a 1:2 rectangle, so from each region’s reference area the short side is √(area ÷ 2) and the long side is √(area × 2). These are the four common sizes:
| Region | Area (m²) | Size (cm) | Size (ft) |
|---|---|---|---|
| Kyōma (Kansai) | 1.82 | 95.3939 × 190.788 | 3.12972 × 6.25944 |
| Chūkyōma (Nagoya area) | 1.66 | 91.1043 × 182.209 | 2.98899 × 5.97797 |
| Edoma (Kantō / most common) | 1.55 | 88.0341 × 176.068 | 2.88826 × 5.77651 |
| Danchima (apartment blocks) | 1.45 | 85.1469 × 170.294 | 2.79353 × 5.58707 |
Dimensions are approximate, derived from each mat’s reference area assuming the standard 1:2 shape.
A tatami mat is a rectangle twice as long as it is wide (a 1:2 ratio). For real-estate area this tool uses 1 jō = 1.62 m² (Japan’s Fair Competition Code minimum), which is about 17.4375 sq ft per mat.
The physical size of a real mat depends on the region, so the cm and feet figures in the table below are the four common regional sizes, derived from each mat’s reference area assuming the standard 1:2 shape.
Real tatami mats vary by region, so “jō” is not one fixed area. Japan’s Fair Competition Code for real-estate advertising sets a minimum of 1.62 m² per jō, and this converter uses 1 jō = 1.62 m². Regional mats differ: Kyōma ≈ 1.82 m², Chūkyōma ≈ 1.66 m², Edoma ≈ 1.55 m², and Danchima (apartment) ≈ 1.45 m² (reference values).
Two tatami mats make one tsubo, and the mats set the module of a traditional Japanese room.
← All Japanese units converters
1 jō = 17.4375 sq ft (about 1.62 m²). Going the other way, 1 sq ft = 0.0573476 jō. A tatami mat is a rectangle twice as long as it is wide (a 1:2 ratio). For real-estate area this tool uses 1 jō = 1.62 m² (Japan’s Fair Competition Code minimum), which is about 17.4375 sq ft per mat.
Type a number into either box of the converter above and the other value appears instantly; use the ⇄ button to swap which unit is on the left. All figures are rounded to 6 significant figures and calculated in your browser.
