The Census Bureau’s American Community Survey (ACS) releases estimates every 5 years; they include margins of error for each individual value. However, if adding several values are added together margins of error for the sum must be recalculated. The ACS Statistical Calculator can assist with that.
Don’t worry if you can’t remember how to calculate the margin of error for a sum of values or how to calculate the margin of error for a derived ratio. Katherine Curtis, UWEX Demographic Specialist, shared this online calculator [Excel Download], developed by the Oklahoma Department of Commerce, that makes it easy to calculate margins of error for sums, percentages and ratios.
If you need a refresher on these statistical measures (what they are and why they are important) the Census provides free guides developed specifically for a variety of users, including non-statisticians and the general public.