Convert Dunam (Ottoman) to Chō
Convert dunams to chōs instantly. 1 dunam (ottoman) = 0.1348947704 chō — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Chō to Dunam (Ottoman) converter for the reverse conversion.
Units explained
Dunam (Ottoman)
An Ottoman dunam was a historical unit of area used across the Ottoman Empire, approximately 1337.8 m². The value varied somewhat by region.
Originated as the area a yoke of oxen could plow in a day, a measure used across much of the Mediterranean. Standardized in different regional ways.
Ottoman dunams appear in pre-20th-century land records across the former Ottoman Empire. Modern usage has shifted to metric dunams (exactly 1000 m²).
Traditional Ottoman unit; largely superseded by metric dunam.
Chō
A chō is a Japanese unit of large-scale area equal to approximately 9917.36 m² (about 0.991 hectare or 2.45 acres). It equals 3,000 tsubo.
Traditional Japanese land area unit, used historically for rice paddies and large estates.
Chōs appear in Japanese agricultural records and historical land documents. Modern usage favors hectares for new transactions but legacy records remain.
Traditional Japanese unit; standardized via the tsubo definition.
Dunam (Ottoman) to Chō conversion formula
The relationship between dunams and chōs:
To convert dunams to chōs, multiply the value in dunams by 0.1348947704. To reverse, multiply chōs by 7.4131858275.
How to use this converter
Type a value into the calculator. The result in chōs updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Chō to Dunam (Ottoman) converter for the reverse direction.
Step-by-step: convert dunams to chōs
- Write down the value in dunams (dunam).
- Multiply that value by the factor 0.1348947704.
- The product is the equivalent value in chōs (chō).
- To reverse, multiply the chō value by 7.4131858275.
Worked examples
Example 1 — Convert 1 dunam to chō:
1 × 0.1348947704 = 0.1348947704 chō
Example 2 — Convert 100 dunam to chō:
100 × 0.1348947704 = 13.4894770382 chō
Real-world example — Coastal cruise distances
A 10-dunam (ottoman) coastal sailing route converts to a different value in chōs — useful for cruise operators who switch between maritime, aviation, and road-distance units depending on the leg of the trip.
10 dunam × 0.1348947704 = 1.3489477038 chō
Real-world example — Road-sign distances across systems
A 100-dunam (ottoman) road sign converts cleanly into chōs — exactly the conversion drivers planning trips abroad rely on when reading road signs in a different measurement system.
100 dunam × 0.1348947704 = 13.4894770382 chō
Real-world example — Endurance race distances
A 50-dunam (ottoman) cycling or running race converts to a recognizable distance in chōs. Endurance athletes coming from a different measurement system use this conversion to compare training plans across regions.
50 dunam × 0.1348947704 = 6.7447385191 chō
Dunam (Ottoman) to Chō conversion table
Standard reference values for converting dunams to chōs:
| Dunam (Ottoman) [dunam] | Chō [chō] |
|---|---|
| 0.01 | 0.0013489477 |
| 0.1 | 0.013489477 |
| 1 | 0.1348947704 |
| 2 | 0.2697895408 |
| 3 | 0.4046843111 |
| 4 | 0.5395790815 |
| 5 | 0.6744738519 |
| 10 | 1.3489477038 |
| 20 | 2.6978954076 |
| 30 | 4.0468431115 |
| 40 | 5.3957908153 |
| 50 | 6.7447385191 |
| 100 | 13.4894770382 |
| 500 | 67.4473851912 |
| 1000 | 134.8947703824 |
Frequently asked questions
How many chōs is 1 dunam (ottoman)?
How do I convert dunams to chōs?
How do I convert chōs back to dunams?
How many chōs is 100 dunams?
Popular area unit conversions
Convert Dunam (Ottoman) to other area units
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Metric / SI (5 units)
Imperial / US Customary (3 units)
Other Regional (9 units)
Sources & references
Conversion factor (1 dunam = 0.1348947704 chō) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.