What Was the U.S. Population in 2018
At the start of 2018, the U.S. population stood at about 327.2 million residents according to U.S. Census Bureau estimates released in that year. This total reflects decennial census counts, ongoing demographic trends, and the effects of births, deaths, and migration. Understanding this figure requires clear definitions, sources, and comparisons. This profile explains how the number is defined, measured, and used, and why estimates can change over time. The following sections provide an evergreen explanation of the 2018 population and its context for future reference.
Official 2018 U.S. Population Estimate
Key Estimate and Sources
The U.S. Census Bureau’s vintage 2018 population estimates, released in 2019, provide the authoritative baseline. These estimates incorporate the 2010 Census results and are adjusted for components of change, including births, deaths, and migration. The reported overall U.S. population at the April 1, 2010 Census was 308,745,538. By July 1, 2018, the estimated population had risen to about 327,167,434. The following table summarizes the key verified attributes of this estimate.
| Attribute | Verified Detail | Source Type |
|---|---|---|
| Reference Date | July 1, 2018 | U.S. Census Bureau |
| Estimated Population | 327,167,434 | U.S. Census Bureau Vintage 2018 Estimates |
| Prior Decennial Census | 308,745,538 on April 1, 2010 | 2010 U.S. Census |
| Approximate Net Annual Growth Rate | 0.7% around 2018 | Derived from Census estimates and components of change |
Definitions: How the Population Figure Is Determined
Population estimates rely on specific definitions and methods. These clarify what is being counted and how changes are measured.
- Resident Population: People living in the 50 states and the District of Columbia, including citizens, non-citizen permanent residents, and non-citizen long-term visitors, excluding those abroad.
- Components of Change: The population change across a year is driven by births, deaths, and net migration (the difference between incoming and outgoing movements).
- Census Baseline: The 2010 Census count serves as the foundation for subsequent estimates, with each year’s estimate adjusted by recorded components of change.
Context: U.S. Population Trajectory Around 2018
Looking at trends before and after 2018 helps explain the significance of this estimate and how it compares to other periods. The table below places 2018 in context with selected earlier and later benchmarks.
| Date or Period | Estimated Population | Notes |
|---|---|---|
| April 1, 2010 (Census) | 308,745,538 | Official decennial count |
| July 1, 2015 | ~321,400,000 | Midway between 2010 and 2020 |
| July 1, 2018 | ~327,167,434 | Focus year of this profile |
| July 1, 2020 | ~331,449,281 | Later benchmark for comparison |
Between 2010 and 2018, the population increased by roughly 18.4 million, or about 6%. The pace of growth moderated after 2010, reflecting changes in fertility, mortality, and migration patterns. Growth from 2018 to 2020 remained steady but showed early signs of further slowdowns that became more pronounced in later years.
Demographic Breakdown in 2018
Understanding the composition of the population adds depth to the total number. In 2018, the U.S. population included diverse age, racial, ethnic, and geographic groups. Although precise percentages evolve, the broad patterns are well established.
- Age Distribution: The largest share was in the working-age groups (18 to 64), with a growing segment aged 65 and older, reflecting the aging of the Baby Boom cohort.
- Racial and Ethnic Diversity: No single group represented an absolute majority; the population included substantial proportions of White, Hispanic, Black or African American, Asian, and other races, with many people identifying with multiple races.
- Geographic Distribution: The South and West regions contained the largest shares of population growth, while the Northeast and Midwest grew more slowly.
Methodology Notes and Limitations
It is important to recognize the assumptions and limitations behind population estimates.
- Estimates Are Derived: The 2018 figure is not a direct count but an estimate built from the 2010 Census and subsequent vital statistics and migration data.
- Timing and Revisions: Estimates are revised in later years as more complete data become available; the 2018 estimate may differ slightly from earlier provisional releases.
- Residency Criteria: The count generally includes people residing in the U.S. on the reference date and excludes certain groups living abroad, with adjustments documented in technical reports.
Why the 2018 Population Estimate Matters
Population totals underlie legislative apportionment, funding formulas, research, and planning. The 2018 estimate captures a specific point in ongoing demographic change and is used as a baseline for comparisons and projections. By clarifying definitions, methods, and context, this profile supports informed, durable use of the figure for years to come.