A dunam, also known as a donum or dunum and as the old, Turkish, or Ottoman stremma, was the Ottoman unit of area equivalent to the Greek stremma or English acre, representing the amount of land that could be ploughed by a team of oxen in a day. The legal definition was “forty standard paces in length and breadth”, but its actual area varied considerably from place to place, from a little more than 900 m² in Ottoman Palestine to around 2500 m² in Iraq.
The unit is still in use in many areas previously ruled by the Ottomans, although the new or metric dunam has been redefined as exactly one decare (1000 m²), like the modern Greek royal stremma.
The name dunam, from the Ottoman Turkish donmek (“to turn”) appears to be a calque of the Byzantine Greek stremma and had the same size. It was likely adopted by the Ottomans from the Byzantines in Mysia-Bithynia.
The Dictionary of Modern Greek defines the old Ottoman stremma as approximately 1,270 m², but Costas Lapavitsas used the value of 1,600 m² for the region of Naoussa in the early 20th century.
In Israel, Palestine, Syria, Jordan, Lebanon and Turkey, the dunam is 1,000 square metres (10,764 sq ft), which is 1 decare. Before the end of the Ottoman Empire and during the early years of the British Mandate for Palestine, the size of a dunam was 919.3 square metres (9,895 sq ft), but in 1928, the metric dunam of 1,000 square metres (0.10 ha) was adopted, and this is still used.
A metric dunam is equal to:
- 1,000 square metres (exactly)
- 10 ares (exactly)
- 1 decare (exactly)
- 0.1 hectares (exactly)
- 0.001 square kilometres (exactly)
- 0.247105381 acres (approx)
- 1,195.99005 square yards (approx)
- 10,763.9104 square feet (approx