# National Population Projections

View all population data

**A new round of national and 50-state population projections for 2030-2050, benchmarked on the 2020 Census, will be available by Summer 2024.**

These population projections for the nation overall, and for all 50 states (and the District of Columbia), were produced and released by the Cooper Center in December 2018. The projections, which were produced using the most recent population estimates and census data from the U.S. Census Bureau, detail changes between 2020 and 2040 in overall population and in subgroups by age and sex.

Cooper Center projections have an outstanding reputation and are widely used by many states and federal agencies, including the Congressional Budget Office. The Center’s 2018 projections for 2020 are highly accurate compared to the 2020 actual Census count, and the Census Bureau frequently refers data inquiries to the Cooper Center website.

Citation: *University of Virginia Weldon Cooper Center. (2018). National Population Projections. Retrieved from **https://coopercenter.org/national-population-projections*

## National Population Projections Data

The following Excel files contain aggregate population data for each state and the nation.

- Total Population
- Age and Sex
*The excel document contains several worksheets; please click on the tabs at the bottom of the document to view the 2020, 2030, and 2040 projections as well as percent population 65+ and median age.* - Methodology (you can also view the methodology below by clicking on the +)

- State and National Projections Methodology
Below are the steps we followed when developing projections for the nation, the 50 states, and the District of Columbia for 2020, 2030, and 2040. The projections include total population, by five-year age groups, and by gender

We use the Hamilton-Perry approach, which is a reduced form of the cohort-component method. Detailed national characteristics are equal to the sum of the projections for each of the 50 states and D.C. State population projections are controlled to the national total; age is controlled to the state total population; and sex is controlled to each age-group.

**Input Data:**U.S., 50 states, and D.C. population for:- 1990 (1 April count) – by 18 age cohorts
- 2000 (1 April count) – by 18 age cohorts
- 2010 (1 April count) – by 18 age cohorts, divided into male, female, and total
- 2017 (1 July estimate by Census Bureau) – total

## TOTAL POPULATION PROJECTIONS

### 2020 Total Population

The exponential growth rate for each of the 50 states and D.C., is calculated using population totals from 2010 and 2017. Using 2017 as the launch year, we apply this exponential growth rate to get the final state level projections for 2020. The projected U.S. population for 2020 is set to the sum of the state populations. This is the final national level population projection for 2020.

### 2030 and 2040 Total Population

We generate CPRs (child population ratio) and CCRs (cohort change ratio) for each age cohort of the

U.S. population, with data from 1990, 2000, and 2010; and use the average of the CCR and CPR values over 1990-2000 and 2000-2010, to smooth out fluctuations.- For cohorts 0-4 and 5-9, CPRs capture the birth rates in the prior decades. We divide the child population by the appropriate population of child-bearing age to generate the CPRs.
- For cohorts 10-14, …. 60-64, 85+, CCRs measure the combined effects of deaths and migration. We use the ratio of population in an age-group (a) in one decade, to the population in age-group (a-10) in the previous decade, to calculate CCRs.

The projected U.S. population for 2020 for each age-cohort is developed by aging forward the 2010 population using the averaged CPRs and CCRs. The total U.S. population for 2020 from Hamilton- Perry method can be calculated by summing across all age-cohorts. We construct the projected U.S. population for 2020 for each age-interval, by redistributing the U.S. population for 2020 as per the age-distribution of the U.S. population for 2020 from Hamilton-Perry method.

The final national level projection for 2030 is set after calculating the projected U.S. population for 2030 from Hamilton-Perry age forwarding. Next, the total U.S. population for 2030 from Hamilton- Perry method is calculated by summing across all age-cohorts. This is the final national level population projection for 2030. The projected U.S. population for 2030 for each age-interval is set as per the age-distribution of the U.S. population for 2030 from Hamilton-Perry method. Each of the projected state populations for 2030 is again calculated using exponential growth, and the state totals are raked to the national total. This is the final state level projection for 2030. 2040 projections for the US and the states are generated using the same approach and repeating the previous process.

## POPULATION PROJECTIONS BY AGE

For projecting the population by age, we apply the state-specific CPRs and CCRs to age forward the 2010 population for each state. These ratios are developed identically to the methodology for the US described earlier in this document. This generates the proper Hamilton Perry age distribution for 2020 within each state, which can then be applied to the state population for 2020 calculated earlier, in order to get the projected population by age for 2020 for the 50 states and D.C. For the U.S. as a whole, population in each age cohort can be calculated by summing the corresponding population belonging to the age group across each of the states.

This process is repeated for 2030 and 2040 by applying the Hamilton Perry age forwarding to the state population in the immediately preceding decade, and using this age distribution to redistribute the previously calculated state total projections. The national projected population by age for 2030 and 2040 is similarly calculated by summing over the projected age categories across all the states.

## POPULATION PROJECTIONS BY GENDER

Projections by gender are determined by maintaining the population’s age-specific sex-ratio as per the 2010 census. This sex-ratio is applied to the projected population in each age cohort within each state, for 2020, 2030 and 2040. So the gender projections are controlled to the subcategories within the state population projections. The male and female population groups within each age cohort are then summed across all the states, to get the U.S. population projections by gender.

Contact: Shonel Sen, shonel.sen@virginia.edu