Ken to Centimeter Converter
Convert ken to centimeters with our free online length converter.
Quick Answer
1 Ken = 181.8 centimeters
Formula: Ken × conversion factor = Centimeter
Use the calculator below for instant, accurate conversions.
Our Accuracy Guarantee
All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.
Ken to Centimeter Calculator
How to Use the Ken to Centimeter Calculator:
- Enter the value you want to convert in the 'From' field (Ken).
- The converted value in Centimeter will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Length category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Ken to Centimeter: Step-by-Step Guide
Converting Ken to Centimeter involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Ken = 181.8 centimetersExample Calculation:
Convert 10 ken: 10 × 181.8 = 1818 centimeters
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
Need to convert to other length units?
View all Length conversions →What is a Ken and a Centimeter?
The Ken (間) is a traditional Japanese unit of length, primarily used in architecture and related fields. It is fundamentally defined as being equal to 6 Shaku (尺). Based on the modern standardized kanejaku Shaku (10/33 meters), the Ken is equivalent to:
- 6 * (10/33) = 60/33 = 20/11 meters
- Approximately 1.818 meters
- Approximately 5.965 feet
Historically, the Ken represented the interval between pillars in traditional Japanese buildings and served as a fundamental module for architectural design, influencing room sizes and the dimensions of elements like tatami mats.
The centimeter (symbol: cm) is a unit of length equal to exactly one-hundredth of a meter (1/100 m or 0.01 m). It's also equal to exactly 10 millimeters.
The centimeter is part of the International System of Units (SI) and uses the metric prefix "centi-" meaning one-hundredth (from Latin centum, "hundred").
Mathematical Relationships
1 centimeter equals:
- 10 millimeters (mm)
- 0.01 meters (m)
- 0.00001 kilometers (km)
- 0.393701 inches (in)
- 0.0328084 feet (ft)
Key conversion:
- 1 inch = 2.54 cm exactly (this is the official international definition established in 1959)
Why Centimeters?
While the meter is the official SI base unit for length, centimeters are more practical for everyday measurements:
Too small for meters, too large for millimeters: A person who is 1.75 meters tall is more commonly described as 175 centimeters in metric countries. Writing "1.75 m" requires decimals; "175 cm" uses whole numbers.
Human-scale convenience: Most objects people interact with daily—clothing, screens, body measurements, food items—fall naturally into the 1-100 cm range.
Avoids decimal confusion: "15.2 cm" is clearer than "0.152 m" for most people.
Note: The Ken is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Centimeter belongs to the metric (SI) system.
History of the Ken and Centimeter
The concept of the Ken, like the Shaku, originated from Chinese architectural practices (where the equivalent unit is Jian 間). It was adopted into Japan along with other elements of Chinese culture and measurement systems.
- Early Use: The Ken was used early on as a standard interval in temple and palace construction. Its length, however, was not strictly fixed and could vary based on the specific building style, region, or period. It was often tied directly to the prevailing length of the Shaku.
- Standardization Attempts: Over time, particularly during the Edo period (1603–1868), attempts were made to standardize measurements. The Ken became strongly associated with architectural modules. Two prominent regional standards emerged:
- Kyōma (京間): The Kyoto module, typically based on a slightly larger Ken (often around 6.5 Shaku or based on tatami dimensions), leading to larger room sizes.
- Inakama (田舎間) / Edoma (江戸間): The rural or Edo (Tokyo) module, typically adhering more closely to the 6 Shaku standard or sometimes slightly smaller (e.g., 6.3 Shaku), resulting in slightly smaller rooms. This became more common.
- Meiji Restoration (1868 onwards): With the standardization of the Shaku at 10/33 meters in 1891, the Ken was implicitly standardized as 6 Shaku = 20/11 meters (approx. 1.818 m). This is the value generally understood as the modern Ken.
- Metrication: Although Japan officially adopted the metric system, the Ken remains a crucial unit in traditional architecture and related fields.
French Revolution and the Birth of the Metric System
1790s: Revolutionary Innovation: The centimeter was born from the French Revolution's ambition to create a rational, universal measurement system based on nature and decimal mathematics.
The Meter Foundation: In 1791, the French Academy of Sciences defined the meter as one ten-millionth (1/10,000,000) of the distance from the equator to the North Pole along the meridian passing through Paris. The centimeter automatically followed as 1/100 of this meter.
Latin Roots: The prefix "centi-" derives from the Latin centum (hundred), making "centimeter" literally "hundredth of a meter."
1795 Official Adoption: France officially adopted the metric system on April 7, 1795, including the centimeter as a standard subdivision of the meter.
CGS System: The Centimeter's Scientific Era
1874: The Centimeter-Gram-Second System: British scientists James Clerk Maxwell and William Thomson (Lord Kelvin) promoted the CGS system, which used:
- Centimeter for length (instead of meter)
- Gram for mass (instead of kilogram)
- Second for time
Scientific Dominance: The CGS system became the preferred standard for physics and chemistry throughout the late 19th and early 20th centuries. Many scientific formulas and units were developed using centimeters.
Legacy Units: Several units still reflect the CGS heritage:
- Poise (viscosity): measured in gram/(centimeter·second)
- Erg (energy): gram·centimeter²/second²
- Gauss (magnetic field): CGS unit for magnetic flux density
Transition to SI and the Modern Era
1960: The SI System: The International System of Units (SI) was officially established, promoting the meter-kilogram-second (MKS) system instead of CGS.
Centimeter's Continued Relevance: Despite the official SI preference for meters, centimeters remained dominant for everyday measurements because:
- They're more practical for human-scale objects
- They avoid decimals for most common measurements
- They're familiar and intuitive
Global Adoption: Today, 195 of 198 countries use the metric system, with centimeters as the standard for body height, clothing, and everyday measurements. Only the United States, Myanmar, and Liberia officially use non-metric systems.
Common Uses and Applications: ken vs centimeters
Explore the typical applications for both Ken (imperial/US) and Centimeter (metric) to understand their common contexts.
Common Uses for ken
The Ken's primary importance lies in its role as an architectural module:
- Traditional Japanese Architecture: It defines the standard bay (pillar-to-pillar distance) in the ken module system (kenshin system 間真). This dictates the layout and proportions of temples, shrines, traditional houses (minka), teahouses, and castles. Room sizes are often described in terms of tatami mats, whose standard dimensions (historically 1 Ken by 0.5 Ken) are derived from the Ken.
- Construction and Carpentry: Used for planning layouts, cutting timber, and sizing building components like fusuma (sliding doors) and shōji (screens).
- Real Estate and Land: Room sizes in Japan are often measured by the number of tatami mats they can hold (e.g., a "6-mat room" - 六畳 rokujō), which indirectly relates to the Ken. Historically, it was also used for land parcel dimensions.
- Martial Arts: The concept of distance or interval (maai 間合い) between opponents is crucial and sometimes measured or conceptualized in terms of Ken. The length of certain weapons, like the bō (staff), is often around 1 Ken (6 Shaku).
- Traditional Garden Design: Used for establishing proportions and spacing elements within Japanese gardens.
- Cultural and Historical Context: Understanding the Ken is essential for interpreting historical architectural plans, documents, and cultural descriptions of space.
When to Use centimeters
Medical and Healthcare
Growth Charts: Children's height is tracked in centimeters from birth:
- Pediatricians plot growth on percentile charts
- Birth length recorded in cm (typically 45-55 cm)
- Annual height measurements track development
Medical Measurements:
- Wound size: "3 cm laceration"
- Tumor diameter: measured in cm for staging
- Organ size: "enlarged liver extending 4 cm below rib cage"
- Dilation during childbirth: measured in cm (0-10 cm)
Medical Equipment:
- Blood pressure cuff width: 12-13 cm for adults
- Surgical incision length: documented in cm
- Catheter diameter: measured in mm, length in cm
Education and School Supplies
Rulers and Measuring Tools: Most rulers worldwide show centimeters:
- Standard ruler: 15 cm or 30 cm length
- Meter stick: 100 cm with cm markings
- Tape measures: marked in cm (and meters)
Paper Sizes (International ISO 216 Standard):
- A4 paper: 21 × 29.7 cm (most common worldwide)
- A5 paper: 14.8 × 21 cm (half of A4)
- A3 paper: 29.7 × 42 cm (double A4)
- Letter size (US): 21.6 × 27.9 cm (8.5 × 11 inches)
School Supplies:
- Pencil length: 19 cm (new)
- Notebook width: 15-21 cm
- Eraser length: 4-6 cm
Construction and Home Improvement
Tile Sizes: Floor and wall tiles measured in cm:
- Small tiles: 10×10 cm
- Medium tiles: 30×30 cm
- Large format tiles: 60×60 cm or 80×80 cm
- Subway tiles: 7.5×15 cm
Furniture Dimensions:
- Coffee table height: 40-50 cm
- Dining table height: 75 cm (standard)
- Chair seat height: 45-50 cm
- Sofa seat depth: 50-60 cm
Door Measurements:
- Standard interior door width: 80-90 cm
- Standard door height: 200-210 cm
- Door thickness: 3.5-4.5 cm
Art, Design, and Photography
Photo Print Sizes:
- 10×15 cm (4×6 inches) - standard print
- 13×18 cm (5×7 inches)
- 20×25 cm (8×10 inches)
- 30×40 cm (12×16 inches)
Canvas and Frame Sizes: Art supply stores sell in metric:
- Small canvas: 20×25 cm
- Medium canvas: 30×40 cm
- Large canvas: 50×70 cm
Drawing and Design:
- Technical drawings: dimensioned in cm or mm
- Graph paper: 0.5 cm or 1 cm grids
- Architectural scales: often use 1:50 or 1:100 (cm-based)
Sports and Recreation
Swimming Pool Depth: Measured in cm or meters:
- Shallow end: 90-120 cm
- Deep end: 180-300 cm
- Competition pool depth: minimum 200 cm
Bicycle Frame Sizes: Road bikes measured in cm:
- Small frame: 48-52 cm
- Medium frame: 54-56 cm
- Large frame: 58-62 cm
Sports Equipment:
- Tennis ball diameter: 6.5-6.7 cm
- Golf ball diameter: 4.3 cm
- Basketball diameter: 24 cm
Additional Unit Information
About Ken (ken)
How long is a Ken?
The modern standard Ken is defined as 6 Shaku. Using the standardized kanejaku Shaku (10/33 m):
- 1 Ken = 20/11 meters
- Approximately 1.818 meters
- Approximately 181.8 centimeters
- Approximately 5.965 feet
- Approximately 71.58 inches Historical and regional variations (like the kyōma) existed, often resulting in slightly different lengths.
How does the Ken relate to the Shaku?
The Ken is a direct multiple of the Shaku:
- 1 Ken = 6 Shaku
Is the Ken related to the Tatami mat?
Yes, very closely. The standard size of a tatami mat was traditionally defined in relation to the Ken, typically 1 Ken long by 0.5 Ken wide (though dimensions varied slightly with regional modules like kyōma and inakama). Room sizes are often measured by the number of tatami mats they contain.
Is the Ken an SI unit?
No, the Ken is not an SI unit. It is a traditional Japanese unit belonging to the Shakkanhō (尺貫法) system. The SI base unit for length is the meter (m).
Is the Ken still used today?
Yes. While the metric system is the official standard in Japan for commerce and science, the Ken remains highly relevant and actively used in:
- Traditional Japanese architecture, design, and construction.
- Carpentry and traditional crafts.
- Real estate descriptions (indirectly via tatami count).
- Martial arts contexts.
- Cultural and historical studies.
- Traditional garden design.
Conversion Table: Ken to Centimeter
| Ken (ken) | Centimeter (cm) |
|---|---|
| 0.5 | 90.9 |
| 1 | 181.8 |
| 1.5 | 272.7 |
| 2 | 363.6 |
| 5 | 909 |
| 10 | 1,818 |
| 25 | 4,545 |
| 50 | 9,090 |
| 100 | 18,180 |
| 250 | 45,450 |
| 500 | 90,900 |
| 1,000 | 181,800 |
People Also Ask
How do I convert Ken to Centimeter?
To convert Ken to Centimeter, enter the value in Ken in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our length converter page to convert between other units in this category.
Learn more →What is the conversion factor from Ken to Centimeter?
The conversion factor depends on the specific relationship between Ken and Centimeter. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.
Can I convert Centimeter back to Ken?
Yes! You can easily convert Centimeter back to Ken by using the swap button (⇌) in the calculator above, or by visiting our Centimeter to Ken converter page. You can also explore other length conversions on our category page.
Learn more →What are common uses for Ken and Centimeter?
Ken and Centimeter are both standard units used in length measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our length converter for more conversion options.
For more length conversion questions, visit our FAQ page or explore our conversion guides.
Helpful Conversion Guides
Learn more about unit conversion with our comprehensive guides:
📚 How to Convert Units
Step-by-step guide to unit conversion with practical examples.
🔢 Conversion Formulas
Essential formulas for length and other conversions.
⚖️ Metric vs Imperial
Understand the differences between measurement systems.
⚠️ Common Mistakes
Learn about frequent errors and how to avoid them.
All Length Conversions
Other Length Units and Conversions
Explore other length units and their conversion options:
Verified Against Authority Standards
All conversion formulas have been verified against international standards and authoritative sources to ensure maximum accuracy and reliability.
National Institute of Standards and Technology — Official US standards for length measurements
Bureau International des Poids et Mesures — International System of Units official documentation
Last verified: February 19, 2026