I doesn't work on my version either (Qgis 2.0 - Windows7-64-Pro) but you can make the calculation in the .dbf file and then open the .shp file with Qgis. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20140207/6ec9e570/attachment.html>