Square Metre, Dunam and Hectare Converter
Convert between square metres, dunams (dönüm), decares, evlek, ares, hectares, square kilometres, acres and square feet. A dunam is taken as 1,000 m²; the old Ottoman dönüm found in old documents can be chosen too.
- Conversion factor1 dunam = 1,000 m²
- Square metres1,000 m²
- Dunams (dönüm)1 dunam
- Hectares0.1 ha
In every unit
How it is calculated
The dunam (dönüm) is the traditional Turkish unit for land and fields; the Cadastre Law No. 3402 in force still speaks of “40 dönüm” and “100 dönüm” in art. 14 without defining it. The last statutory definition is art. 5 of Law No. 4753 on Providing Land to Farmers (Official Gazette 15 June 1945, No. 6032): “A dönüm is a place of one thousand square metres.” That law has since been repealed; Law No. 3083, provisional art. 3, refers to it as repealed by art. 8 of Law No. 1617. A dunam is still taken as 1,000 m², one decare. The Ottoman “şer‘î dönüm” was 40 × 40 = 1,600 square architect’s cubits; the TDV Encyclopaedia of Islam gives 916.8 or 919.302 m² and notes that after the “new dönüm” of 1881 it was called the “old dönüm”; the calculator uses 919.302 m². It also varied by region. An evlek is traditionally a quarter dönüm (TDV), 250 m² with today’s dönüm. Neither the evlek nor the old dönüm is a legal unit. Law No. 3516 on Measures and Calibration, art. 6, requires international units in official documents and in registers kept under law, so Turkish land records give area in square metres. The hectare (1 ha = 10,000 m²) and the are (1 a = 100 m²) are the units for land area (SI Brochure, Table 8); a decare is 10 ares.
dunam = m² ÷ 1,000 · ha = m² ÷ 10,000The value is first turned into square metres, then divided by the target unit’s size in m². 1 are = 100 m², 1 decare = 10 ares, 1 hectare = 100 ares, 1 km² = 100 hectares.- Enter the area and the unit it is in (for example 2,500 square metres).
- Choose the unit to convert to; the result and the conversion factor are shown.
- Square metres, dunams and hectares are always listed too; the table gives every unit.
Example
A 2,500 m² field is 2,500 ÷ 1,000 = 2.5 dunams and 2,500 ÷ 10,000 = 0.25 hectares. 3 hectares are 30,000 m², or 30 dunams. An acre is 4,046.86 m², about 4.05 dunams.
Frequently asked questions
How many square metres is a dunam?
A dunam is 1,000 m², the same as a decare. A quarter dunam, an evlek, is 250 m².
How many dunams are in a hectare?
A hectare is 10,000 m², or 10 dunams. A square kilometre is 100 hectares, or 1,000 dunams.
Is a dunam the same as a decare?
In size they are the same, 1,000 m². Decare is the metric name, meaning 10 ares; its symbol is “daa”, the deca prefix “da” plus the are “a” (a prefix symbol never stands alone, SI Brochure §3). Dönüm is the traditional name for the same area.
How large is the old Ottoman dönüm?
According to the TDV Encyclopaedia of Islam, the Ottoman “şer‘î dönüm” was 1,600 square architect’s cubits, 916.8 or 919.302 m²; the calculator uses 919.302 m². It is a traditional measure with no legal definition, and it varied by region: the same source gives 1,225 square cubits (701.9 m²) around Istanbul and 2,025 (1,160.4 m²) in Anatolia. For an old document, check the square-metre figure in the land registry record.
Do Turkish title deeds give area in dunams?
No. Law No. 3516 on Measures and Calibration, art. 6, requires international units in official and private contracts, all documents and registers kept under law, so the land register and title deeds give area in square metres (title records made before 1 January 1933 are outside that law under art. 3(c)). Sales talk may use dunams, but the official figure is in m²; divide it by 1,000 to get dunams.
How many square metres is an acre?
An acre is 43,560 square feet, or in UK law 4,840 square yards; with the international foot (0.3048 m) and yard (0.9144 m) that is exactly 4,046.8564224 m², about 4 dunams or 0.4 hectares. The older US acre based on the survey foot (4,046.8726 m²) should, says NIST, be used after 31 December 2022 only for historic and legacy records.
Source
- Law No. 4753 on Providing Land to Farmers, art. 5 (Official Gazette 15.06.1945, No. 6032): the dönüm is 1,000 m²
- Law No. 3083 on Agrarian Reform in Irrigation Areas, provisional art. 3 (Law No. 4753 repealed)
- Cadastre Law No. 3402, art. 14 (“40 dönüm”, “100 dönüm”)
- Law No. 3516 on Measures and Calibration, arts. 3(c) and 6 (Official Gazette 21.01.1989, No. 20056)
- TDV Encyclopaedia of Islam: “Dönüm” (F. Emecen, vol. 9, 1994, Turkish): old dönüm and evlek
- BIPM, The SI Brochure (9th ed.), Table 8: are (1 a = 10² m²) and hectare (1 ha = 10⁴ m²); §3: prefix symbols
- NIST: Revised unit conversion factors after the US survey foot (acre = 43,560 ft² = 4,046.856 422 4 m²)
- UK Weights and Measures Act 1985, Schedule 1 Part VI (yard = 0.9144 m, acre = 4,840 sq yd)