I have always calculated 7 to 8 syns for a half avocado, depending on size. I am fairly sure that's what it says in my book, although right now I can't find it (having a tidy up - can't find anything!!) - I do remember a consultant telling me that avocados are very good for you but if you have one, that's all your syns for the day.
But I would rather use my syns on something like that, rather than junk food. Lots of vitamins and good fats in an avocado.
If you are doing it by weight, then don't syn the bits you aren't eating! Unless you are munchng your way through the skin and the stone (and how unlikely is that!!) then just weigh the flesh.
