What Is Ken?
Ken is a traditional Japanese unit of length. It is mainly used in building design to measure the spacing between pillars and the size of rooms. One ken is a little shorter than 2 meters and a little shorter than 6 feet.
Definition
In modern terms, one ken is defined as exactly six Japanese shaku.
Since one shaku is about 0.303 meter, one ken is about:
- 1.818 meter
- 181.8 centimeter
- About 5.97 feet, which is almost 6 feet
So you can think of one ken as almost the height of a tall adult person standing up.
History / Origin
The ken comes from old Japanese architecture. Long ago, builders needed a simple way to plan how far apart to place wooden pillars in houses, temples, and shrines. They used the shaku as a basic unit and made the ken from several shaku put together.
At first, the exact length of one ken was not the same everywhere. It could change by region and time period. In many cases it was somewhere between about 1.79 meter and 1.91 meter. This means carpenters in different areas might have used slightly different kens.
When Japan adopted the metric system, the shaku and ken were given fixed metric values. That is when one ken was set to exactly six shaku, or about 1.818 meter. Even after the metric system became standard, carpenters and builders kept using the ken to plan traditional style buildings.
Symbol & Abbreviation
The ken is written in Japanese with the character:
- 間 which is read as “ken” in this context
Common ways to show ken are:
- 間 after a number, for example 3間
- The word ken in roman letters, for example 3 ken
There is no official international symbol like the ones for meter or foot. In English texts, people usually just write the word “ken” after the number.
Current Use Around the World
Today, ken is mainly used in Japan and mostly in special areas, not in everyday life.
It is still used for:
- Traditional architecture planning the spacing between pillars and beams
- Tatami layouts planning rooms made from tatami mats, because their sizes are linked to the ken
- Temples, shrines, and tea houses where designs follow old rules based on ken units
- Historical studies when people study or restore old buildings
Outside Japan, the ken is not used in normal building work. However, people who study Japanese design, martial arts training halls, or traditional gardens may still talk about measurements in ken to stay close to the original style.
Example Conversions
These examples use one ken as 1.818 meter.
- 1 ken
- About 1.818 meter
- About 181.8 centimeter
- About 5.97 feet
- About 71.4 inches
- 2 ken
- About 3.636 meter
- About 363.6 centimeter
- About 11.94 feet which is almost 12 feet
- 3 ken
- About 5.454 meter
- About 545.4 centimeter
- About 17.91 feet which is almost 18 feet
- Half a ken 0.5 ken
- About 0.909 meter
- About 90.9 centimeter
- About 2.99 feet which is almost 3 feet
To change kens into meters you can use this simple rule:
- meters = number of ken × 1.818
To change kens into feet you can use this rule:
- feet = number of ken × about 5.97
Related Units
The ken is part of a family of traditional Japanese units.
- Shaku
- Basic Japanese unit of length
- One ken equals 6 shaku
- Sun
- Smaller unit used in carpentry and crafts
- Ten sun make one shaku
- Jo
- Sometimes used as another name for a certain length related to building spans
- Tsubo
- Unit of area used for land and floor space
- One tsubo is the area of a square that is 1 ken by 1 ken
- So one tsubo is about 3.3 square meters
Today, meters and centimeters are used for most tasks, but these traditional units like ken and tsubo are still important in older style building work.
FAQs
How long is one ken in meters
One ken is about 1.818 meter. This is a fixed modern value based on six shaku.
How many feet are in one ken
One ken is about 5.97 feet, which people usually round to about 6 feet for simple everyday use.
Is the ken still used in Japan today
Yes, but not in normal daily life. The ken is mostly used in traditional architecture, temple and shrine design, and by carpenters who follow old styles.
Why was the ken important in Japanese buildings
The ken helped builders keep pillar spacing and room sizes regular and easy to plan. Many classic Japanese buildings were designed as whole numbers of ken in each direction.
Is ken an official unit like the meter
No. Japan now uses the metric system officially. The ken is a traditional unit that survives in special fields such as historical building work and cultural studies.
How does ken relate to tatami mats
Traditional tatami mat sizes are linked to the ken. Rooms are often planned as a certain number of ken by a certain number of ken, which then fit an exact number of tatami mats.
