Hi I wrote this during the summer after a conversation on the list with Felix. Currently the convert filter will only convert from meters to feet as it was for compatibility with some hard wired rule back before the style system. It also didn't work if the original value had a unit. Eg: '${ele|"m=>ft"}' The patch allows for length conversions between m, km, mi, ft and speed conversions of km/h (kmh, kmph), mph, knots. New ones can easily be added. It will also take into account any unit that already exists. So for example if you have ${val|m=>ft} Then val will be assumed to be in meters if there is no unit. val=10 --> 33 if a unit is given, then it converts from that, so if already in feet the value will be unchanged. val=10ft --> 10 val=10km --> 32,808 If it can't work out what to do then the value is unchanged. ..Steve