The stremma (Greek: στρέμμα, plural στρέμματα) is a Greek unit of land area, equal to 1,000 square metres, also called the 'royal' stremma. The name comes from a root meaning 'to turn', presumably referring to the amount of land that can be plowed/turned in a day.
The "old", "Turkish", or "Ottoman" stremma was approximately 1,270 m² (Λεξικό, 1998): it was the Greek name of the Ottoman dönüm, which was in turn based on the Byzantine stremma (see below). But the exactly value varied by region.
One stremma is equivalent to:
- 10,763.9 square feet
- 0.247 105 38 international acres
- 0.247 104 39 U.S. survey acres; 1 acre ≈ 4.047 stremmata
- 0.000 386 102 square miles (statute)
- Λεξικό της κοινής Νεοελληνικής (Dictionary of Modern Greek), Ινστιτούτο Νεοελληνικών Σπουδών, Θεσσαλονίκη, 1998. ISBN 960-231-085-5
- for the region of Naoussa in the early 20th century, one researcher uses a value of 1,600 m²: Costas Lapavitsas, "Social and Economic Underpinning of Industrial Development: Evidence from Ottoman Macedonia", Ηλεκτρονικό Δελτίο Οικονομικής Ιστορίας 
- Siriol Davis, "Pylos Regional Archaeological Project, Part VI: administration and settlement in Venetian Navarino", Hesperia, Winter, 2004 
- V.L. Ménage, Review of Speros Vryonis, Jr. The decline of medieval Hellenism in Asia Minor and the process of islamization from the eleventh through the fifteenth century, Berkeley, 1971; in Bulletin of the School of Oriental and African Studies (University of London) 36:3 (1973), pp. 659-661. at JSTOR (subscription required); see also Erich Schilbach, Byzantinische Metrologie (referenced but not seen)