What is Ares to Hectares Converter?
are hectare conversion, European land units This tool runs entirely in your browser. No data is sent to any server, and no signup is needed.
Ares to Hectares Converter
Ares are common in European and South American real estate. 1 hectare = 100 ares = 10,000 m².
Quick reference: ares to hectares
| ares | hectares |
|---|---|
| 1 ares | 0.01 hectares |
| 10 ares | 0.1 hectares |
| 100 ares | 1 hectares |
| 1,000 ares | 10 hectares |
| 10,000 ares | 100 hectares |
About this Land area conversion (Europe)
Ares are common in European and South American real estate. 1 hectare = 100 ares = 10,000 m².
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Frequently asked questions
What is an are?
An are (pronounced "air") is a metric unit of area equal to 100 square meters. Mostly used in Europe and South America for small land parcels.
Is an are the same as a hectare?
No. 1 hectare = 100 ares. An are is a 10m × 10m square; a hectare is a 100m × 100m square.
Where is the are still used?
France, Germany, Switzerland, and parts of South America (Brazil, Argentina) for residential plots. Replaced by m² in most contracts.
How big is 1 hectare in football fields?
About 1.4 American football fields (NFL field is 1.32 acres = 0.534 ha) or 1 international football field (FIFA 100m × 64m = 0.64 ha).
How do I convert between are, hectare, and acre?
1 hectare = 100 ares = 2.471 acres. 1 are = 0.0247 acres. Acres remain US/UK standard; metric prefers hectares.
About ares and hectares
An are is a metric unit of area equal to 100 square metres, equivalent to a 10 m × 10 m square. A hectare is 10,000 square metres, equivalent to a 100 m × 100 m square. The are and hectare are accepted SI-compatible units for land measurement (BIPM SI Brochure, Table 8).
Conversion factor
The are and hectare differ by exactly two orders of magnitude in metric scale (NIST SP 811, Appendix B).
1 are = 100 m² (exact) 1 hectare = 10,000 m² (exact) = 100 ares 1 are = 0.01 hectare (exact) 1 hectare = 2.4710538 international acre (NIST)
Worked example: 450 ares of farmland
A French notaire lists a parcel at 450 ares (a typical mid-size rural plot). To list it in hectares for an international buyer:
- Apply the exact factor: 450 × 0.01 = 4.5 hectare.
- Verify by area: 450 × 100 m² = 45,000 m² = 4.5 ha.
- Cross-check in acres: 4.5 ha × 2.4710538 acre/ha ≈ 11.12 acres.
Reference table of land-area units
| Unit | Square metres | Ares | Hectares | Acres |
|---|---|---|---|---|
| 1 centiare | 1 | 0.01 | 0.0001 | 0.000247 |
| 1 are | 100 | 1 | 0.01 | 0.02471 |
| 1 decare (Greek stremma) | 1,000 | 10 | 0.1 | 0.2471 |
| 1 acre (US/UK) | 4,046.8564 | 40.469 | 0.4047 | 1 |
| 1 hectare | 10,000 | 100 | 1 | 2.4711 |
| 1 km² | 1,000,000 | 10,000 | 100 | 247.105 |
Pitfalls and accuracy notes
- Are vs acre: phonetically close, factor of 40.469 different. Always check the spelling in the deed.
- French notation: 1 a 50 ca means 1 are + 50 centiares = 150 m². The "ha a ca" convention is still on older French and Swiss documents.
- Survey vs international acre: the US survey acre is 4,046.873 m², international acre is 4,046.856 m². Difference is 2 parts per million, irrelevant for plots under 10 ha.
- South American hectárea: identical to the metric hectare. Brazilian rural cadastre also uses the alqueire (varies by state: 24,200 m² to 48,400 m²).
When to use this converter
- European real estate listings: French and Swiss notaires often quote ares; multiply by 0.01 for hectares.
- Vineyard and orchard work: rows are typically planned per are.
- Solar PV land planning: a 1 MWp ground-mount array needs roughly 1 hectare; convert from ares quoted in offers.
- Reading old land titles: 19th and early 20th century European deeds use ares and centiares.
Related tools
- Acres to Hectares Converter for US/UK to metric.
- Miles to Kilometres for distance conversion.
- Grams to Ounces for mass conversion.
- Horsepower to Kilowatts for power conversion.
Frequently asked questions
How many ares make one hectare?
Exactly 100 ares = 1 hectare. The hectare is the larger unit by two orders of magnitude.
What does "centiare" mean on a French deed?
1 centiare = 0.01 are = 1 square metre. French deeds sometimes write area as "1 ha 23 a 45 ca", meaning 1 hectare + 23 ares + 45 centiares = 12,345 m².
How does an are compare to a tennis court?
A standard ITF tennis court (singles) is 23.77 m × 8.23 m ≈ 195.6 m² ≈ 1.96 ares. A doubles court (23.77 m × 10.97 m ≈ 260.8 m²) is roughly 2.6 ares.
Where is the are still legally used today?
France, Switzerland, Luxembourg, Slovakia, and some Balkan countries retain the are in cadastral documents. Germany still uses it in some Bavarian and Saxon land registers. Most modern transactions in those countries quote square metres or hectares.
What is the precise hectare-to-acre factor?
1 hectare = 2.4710538147 international acres (NIST SP 811). The international acre is defined as exactly 4,046.8564224 m² since the 1959 international yard agreement.
Sources
- BIPM (2019), The International System of Units (SI), 9th edition, Table 8 (non-SI units accepted for use).
- NIST SP 811 (2008), Guide for the Use of the International System of Units, Appendix B.
- Décret n° 61-501 (France), defines the are and centiare for surveying.
Last updated 2026-05-28.