杜纳亩（奥斯曼土耳其语：دونم; 土耳其语：dönüm），或译为杜纳姆、杜诺亩、杜诺姆、德南，也被称为旧斯特伦马、土耳其斯特伦马或奥斯曼斯特伦马，奥斯曼帝国时期的面积单位，相当于希腊斯特伦马或英国英亩，代表了两头联套的牛一天时间内可耕的土地的面积。其正式的定义是“四十步见方的面积”，但它的实际面积存在很大的地区差异，在巴勒斯坦约为900 m²稍多，而在伊拉克约为2500 m²。

该单位在原奥斯曼帝国统治的地区仍有使用，新杜纳亩或称米制杜纳亩被重新定义为等于1迪卡尔（1000 m²），与现代希腊的皇家斯特伦马相等。

A dunam (Ottoman Turkish:دونم‎; Turkish:dönüm), 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 Palestine to around 2500 m² in Iraq.