Resize the Chart
There is a
way to make all of your charts the same consistent size. This is a
useful tool, especially if you are going to include several charts
in a PowerPoint presentation.
Try it:
Edit the Chart Size
Select the
chart.
Go to PivotTable Tools.
Look for
Format->Size.

Size
lets you change the height and width of your chart. You can use the
arrows or type in a value if you wish.