Convert Acre to Dunam (Metric)
Convert acres to dunams instantly. 1 acre = 4.0468564224 dunam (metric) — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Dunam (Metric) 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.
Dunam (Metric)
A metric dunam is a unit of land area equal to exactly 1000 m² (0.1 hectare or about 0.247 acre). Used widely in Israel, Turkey, and the Middle East.
Originally an Ottoman unit of variable size (see Ottoman dunam). The metric dunam was standardized at exactly 1000 m² in the 20th century for ease of conversion.
Metric dunams are the standard land measurement unit in Israel for both residential and agricultural property. Also widely used in Turkey, Cyprus, and other former Ottoman territories.
Standardized at 1000 m² in 20th century; Ottoman origin.
Acre to Dunam (Metric) conversion formula
The relationship between acres and dunams:
To convert acres to dunams, multiply the value in acres by 4.0468564224. To reverse, multiply dunams by 0.2471053815.
How to use this converter
Type a value into the calculator. The result in dunams updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Dunam (Metric) to Acre converter for the reverse direction.
Step-by-step: convert acres to dunams
- Write down the value in acres (ac).
- Multiply that value by the factor 4.0468564224.
- The product is the equivalent value in dunams (dunam).
- To reverse, multiply the dunam (metric) value by 0.2471053815.
Worked examples
Example 1 — Convert 1 ac to dunam:
1 × 4.0468564224 = 4.0468564224 dunam
Example 2 — Convert 100 ac to dunam:
100 × 4.0468564224 = 404.68564224 dunam
Real-world example — Coastal cruise distances
A 10-acre coastal sailing route converts to a different value in dunams — useful for cruise operators who switch between maritime, aviation, and road-distance units depending on the leg of the trip.
10 ac × 4.0468564224 = 40.468564224 dunam
Real-world example — Road-sign distances across systems
A 100-acre road sign converts cleanly into dunams — exactly the conversion drivers planning trips abroad rely on when reading road signs in a different measurement system.
100 ac × 4.0468564224 = 404.68564224 dunam
Real-world example — Endurance race distances
A 50-acre cycling or running race converts to a recognizable distance in dunams. Endurance athletes coming from a different measurement system use this conversion to compare training plans across regions.
50 ac × 4.0468564224 = 202.34282112 dunam
Acre to Dunam (Metric) conversion table
Standard reference values for converting acres to dunams:
| Acre [ac] | Dunam (Metric) [dunam] |
|---|---|
| 0.01 | 0.0404685642 |
| 0.1 | 0.4046856422 |
| 1 | 4.0468564224 |
| 2 | 8.0937128448 |
| 3 | 12.1405692672 |
| 4 | 16.1874256896 |
| 5 | 20.234282112 |
| 10 | 40.468564224 |
| 20 | 80.937128448 |
| 30 | 121.405692672 |
| 40 | 161.874256896 |
| 50 | 202.34282112 |
| 100 | 404.68564224 |
| 500 | 2023.4282112 |
| 1000 | 4046.8564224 |
Frequently asked questions
How many dunams is 1 acre?
How do I convert acres to dunams?
How do I convert dunams back to acres?
How many dunams 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 = 4.0468564224 dunam) 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.