Official State of Iowa Website

Population Estimates

Every year the Census Bureau produces population estimates for the U.S., states, counties, and incorporated places.

National Population Estimates

National population estimates are: 

    • Released monthly
    • For age, sex, race, and Hispanic origin 
    • For resident, resident plus armed forces overseas, civilian, and civilian non-institutional populations
    • Benchmarked annually to the latest cycle of July estimates

State Population Estimates

State population estimates are:

    • Released annually in December
    • Show total all-ages resident population and components of population change as of July 1 of the release year
    • Also released for single years of age and sex, and for race detail sometime after December

County Population Estimates

County population estimates are:

    • Released annually, usually in March
    • Show total all-ages resident population and components of population change as of July 1 of the previous year
    • Also released age-race-sex detail sometime after March

City (Incorporated Place) Estimates

Incorporated place population estimates are:

    • Released annually, usually in June
    • Show total all-ages resident population as of July 1 of the previous year 
    • Not released for components of change or for age-race-sex detail

National and State Housing Unit Estimates

Estimates of national and state population in households are released annually. Data in this release include:

    • Persons in households
    • Persons per household
    • Total number of households
    • Households by age of householder
    • Number of housing units

Revisions to Estimates

With each new issue of July 1 estimates, the estimates for all years back to the last decennial census are revised and previously released estimates become superseded. Revisions to estimates are usually due to:

    • Revisions to input data
    • Changes in methodology


How are Estimates Different from Projections?

Generally, estimates are for the past, while projections typically are for future dates.

    • Estimates generally use existing symptomatic data collected from various administrative sources, while projections must assume what demographic trends will be in the future.
    • The Census Bureau uses the latest available estimates as starting points for its U.S. and state population projections.
    • Sometimes the user may see both an estimate and a projection available for the same reference date, which may not agree because they were produced at different times. In such cases, estimates are the preferred data.

More Information

For more information about the Census Bureau's methodology for population estimates, see:

For more information about challenging the Census Bureau's population estimates, see: