Help with more efficient formatting and calculations

Can anyone suggest a more efficient way to format and formulate calculations for the conversion in the attached example. It is always a pain to to re-do the formulas when the percentages change. I have several similar tables that must be summed together to get a consolidated total. There must be a better way to do this, but I'm not sure where to start. Thanks.

You should repost your example including some comments, on the sheet itself, pointing out which formulas you are talking about and what the "percentages" are and when they change.