In the last few weeks, we have received questions on how to calculate margins of error
(MOE) when you add, or subtract, or divide ACS 2005 data. The Census Bureau has some
instructions for applying statistical testing to ACS Data posted at
Using these instructions, I prepared an MS Excel template for calculating MOE for
additions, subtractions, proportions, or percents (please see attached MOE.xls). I am
assuming 90% CI for my calculations. There are three worksheets (one for
additions/subtractions, one for proportions, and one for percents).
Hope you find these useful.