Japan’s unique system of measuring space, particularly in housing and architecture, reflects a blend of tradition and practicality. Here’s a breakdown of this system:
Tatami Mats as a Measure of Space
The traditional Japanese tatami mat, made of woven straw, is a key unit of measurement in Japan. These mats communicate the size of rooms in houses and apartments. A standard tatami mat is approximately 1.8 meters by 0.9 meters in size. However, this can vary, especially in cities like Tokyo, where space is premium and tatami mats might be slightly smaller.
“Jo” as a Counting Unit
“jo” refers to the number of tatami mats that can fit in a room. For instance, a “6-jo room” means a room that can accommodate six tatami mats. This unit is applied to all rooms, including living, dining, and kitchen areas, collectively known as LDK in Japan.
Size Variations
A 4.5-mat room is considered small in Japanese homes, while an 8-10-mat room is relatively large. This contrasts with Western-style homes, where an 8-10 mat room might be a standard bedroom size.
Conversion to Metric and Imperial Units
The table below offers a conversion of “jo” to square meters and square feet, which is helpful for those more accustomed to Western measurement systems. For example, 1 “jo” equals 1.62 square meters or 17.44 square feet.
Tsubo – Another Traditional Measurement
In addition to the tatami-based system, Japan uses the “tsubo” as a unit of area measurement. Historically, one tsubo is equivalent to the area of two tatami mats. This unit is more commonly used to express the overall size of apartments or houses rather than summing up the tatami count of each room. For example, 2 “jo” equals 3.24 square meters or 34.88 square feet.
Understanding these measurement systems is crucial for anyone living in or dealing with property in Japan, as they offer a unique perspective on space utilization and are of cultural significance in Japanese architecture and interior design.
Conversion of “jo” to square meters and square feet
| Tatami Jo | Square Meters | Square Feet |
|---|---|---|
| 1.00 | 1.62 | 17.44 |
| 1.50 | 2.43 | 26.16 |
| 2.00 | 3.24 | 34.88 |
| 2.50 | 4.05 | 43.59 |
| 3.00 | 4.86 | 52.31 |
| 3.50 | 5.67 | 61.03 |
| 4.00 | 6.48 | 69.75 |
| 4.50 | 7.29 | 78.47 |
| 5.00 | 8.10 | 87.19 |
| 5.50 | 8.91 | 95.91 |
| 6.00 | 9.72 | 104.63 |
| 6.50 | 10.53 | 113.34 |
| 7.00 | 11.34 | 122.06 |
| 7.50 | 12.15 | 130.78 |
| 8.00 | 12.96 | 139.50 |
Fg2 assumed (based on copyright claims)., Public domain, via Wikimedia Commons
