Creating dynamic range charts in excel if the headers are already in place

Is it possible to use the Dynamic Range option for charts in Excel 2013 when the headers are already in place?

I have a chart that I set up at the beginning of the year with Budget, Sales, Difference on one axis, and Jan, Feb, Mar… Dec on the other. As I enter each month’s data, I would like to see the chart automatically resize using the dynamic ranges function… is this possible?

I would prefer not to have to enter the months one at a time if I can avoid it.

Any help that anybody can give me would be great… many thanks in advance