Which U.S. counties added the most residents in 2024–2025? Compare official Census estimates, absolute increases, percentage growth and source definitions.
Harris County leads this absolute population-increase ranking with 48,695 residents added. The comparison covers July 1, 2024 to July 1, 2025.
Harris County, Texas added 48,695 residents between July 1, 2024 and July 1, 2025, followed by Collin County, Texas with 42,966. The ten leading gainers added 310,008 residents in total. Only counties with a positive population change enter this increase ranking.
Absolute growth answers a scale question: how many additional residents appear in the dated estimates? It is often useful when discussing service demand, enrollment planning or the size of an area's change. It does not describe the percentage burden on any specific service, nor does it measure construction, employment or housing need.
Why the biggest increase is not the fastest growth rate
Harris County's increase corresponds to 0.97% growth from its 4,996,331 starting residents. By comparison, Jasper County, South Carolina leads the separately qualified percentage-growth ranking at 6.04%. Different starting populations can reverse the order.
Across the full eligible counties universe, 1,862 gained residents, 1,270 lost residents and 12 were unchanged in the most recent interval. A sum of only positive changes is not the same as net population growth: losses must also be included in an exhaustive, compatible total. Use the matching national or state control total for a net-growth comparison.
Comparison universe: 3,144 U.S. counties and county equivalents. Source: PEP Vintage 2025. Population date: July 1, 2025. Growth interval: July 1, 2024–2025. Ties share a competition rank; subsequent ranks skip tied positions. Filters produce a subset of this universe and do not change the national profile rank.
For Harris County, the source reports natural change of 34,861, net domestic migration of -43,377, net international migration of 57,225 and a residual of -14 in the annual interval. Those terms reconcile to its 48,695-resident increase.
Births minus deaths define natural change. Migration components are net measures, not counts of all arrivals or departures. The components describe accounting contributions and do not establish the reasons residents moved. The profile presents the complete reconciliation, including the source residual.
Sources, calculation rules and downloadable results
Source: co-est2025-alldata.csv, Census Population Estimates Program, Vintage 2025, variables POPESTIMATE2024 and POPESTIMATE2025. Density additionally uses 2025 Gazetteer ALAND joined by official code. The retained source snapshot is pep-2025-r1; calculations use unrounded values.
Change order uses 2025 population minus 2024 population. Equal unrounded metric values share a competition rank, and the following rank skips the tied positions. Display rounding can make different underlying values look identical; the table order uses the originals.
Export visible rows after filtering to preserve the displayed subset. Use complete dataset downloads for all observations, or population research tools for a longer comparison. A ranking is a dated descriptive result, not an official forecast. Publication vintages can revise earlier years; retain the release identifier with your research.
