Charts won't fit onto page 1?

I have several reports where the data (monthly sales figures) occupies only a
few lines, less than half the page.
When I construct a chart to display this data and then downsize it to what
looks like well under half a page (i.e. should easily fit on the same page as
the lines of data) it still refuses to go onto the same page and insists on
creating a second page.
Is there some kind of invisible border or wrapper around charts, that is
telling it it's too big to fit - or any other reason?
Many thanks
CW