I asked this question a long time ago (when I was getting my first yorkie

), and the general consenses seemed to be to add a lb or two to the chart.
However, like Majic50 I had a little girl who was a chunky little monkey

, and she also was "off the chart" at different times. But at three years she goes between 5 - 6 lbs.
If I were you, I'd take the chart in one hand, a grain of salt in the other, add a lb or two to whatever it predicts, and then realize your doggie could very well end up being smaller or larger!
how's that for a helpful answer?! lol