Convert Acre to Chō
Convert acres to chōs instantly. 1 acre = 0.4080578322 chō — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Chō to Acre converter for the reverse conversion.
Units explained
Acre
An acre is an imperial unit of area equal to exactly 4046.8564224 m². It is the most widely used non-metric unit for land area, particularly in the US, UK, and India.
Originally defined in medieval England as the area one yoke of oxen could plow in a day, approximately 40 perches by 4 perches. Standardized via the 1959 International Yard and Pound Agreement.
Acres are the standard land measurement unit in the US (real estate, agriculture), the UK (rural property), and widely used in India (alongside hectares and traditional regional units). 1 acre = 4840 sq yd = 43,560 sq ft = 0.4047 hectare.
Medieval English farming origin; modern exact value standardized in 1959.
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.
Acre to Chō conversion formula
The relationship between acres and chōs:
To convert acres to chōs, multiply the value in acres by 0.4080578322. To reverse, multiply chōs by 2.4506330259.
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 Acre converter for the reverse direction.
Step-by-step: convert acres to chōs
- Write down the value in acres (ac).
- Multiply that value by the factor 0.4080578322.
- The product is the equivalent value in chōs (chō).
- To reverse, multiply the chō value by 2.4506330259.
Worked examples
Example 1 — Convert 1 ac to chō:
1 × 0.4080578322 = 0.4080578322 chō
Example 2 — Convert 100 ac to chō:
100 × 0.4080578322 = 40.8057832165 chō
Real-world example — Coastal cruise distances
A 10-acre 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 ac × 0.4080578322 = 4.0805783217 chō
Real-world example — Road-sign distances across systems
A 100-acre 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 ac × 0.4080578322 = 40.8057832165 chō
Real-world example — Endurance race distances
A 50-acre 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 ac × 0.4080578322 = 20.4028916083 chō
Acre to Chō conversion table
Standard reference values for converting acres to chōs:
| Acre [ac] | Chō [chō] |
|---|---|
| 0.01 | 0.0040805783 |
| 0.1 | 0.0408057832 |
| 1 | 0.4080578322 |
| 2 | 0.8161156643 |
| 3 | 1.2241734965 |
| 4 | 1.6322313287 |
| 5 | 2.0402891608 |
| 10 | 4.0805783217 |
| 20 | 8.1611566433 |
| 30 | 12.241734965 |
| 40 | 16.3223132866 |
| 50 | 20.4028916083 |
| 100 | 40.8057832165 |
| 500 | 204.0289160825 |
| 1000 | 408.057832165 |
Frequently asked questions
How many chōs is 1 acre?
How do I convert acres to chōs?
How do I convert chōs back to acres?
How many chōs is 100 acres?
Popular area unit conversions
Convert Acre to other area units
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Metric / SI (16 units)
Imperial / US Customary (14 units)
US Survey (5 units)
Indian Subcontinent (16 units)
Other Regional (10 units)
Scientific / Physics (5 units)
Historical / Pre-metric European (6 units)
Sources & references
Conversion factor (1 ac = 0.4080578322 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.