Definition: European Size Unit
For each activity ("enterprise") on a farm (for instance wheat, dairy cow or vineyard), a standard gross margin (SGM) is estimated, based on the area (or the number of heads) and a regional coefficient. The sum of such margins in a farm is its economic size, expressed in European Size Units (ESU, 1 ESU is a 1200-euro standard gross margin).
Eurostat, Statistics in Focus, No. 20/2009, Office for Official Publications of the European Communities, Luxembourg, 2009