This is less than a one percent fall in Mercer County’s population, from 386,759 in 2020 to 385,898 in 2021.
Mercer County had the 12th largest population in New Jersey in 2021.
The US Census Bureau found more than 73 percent of counties in the US saw a natural decrease in population in 2021. This is up from a 55.5 percent increase in 2020.
The Midwest suffered the most sustained population decreases, with many counties along the US East Coast and through the Rocky Mountains seeing increases.
The US population continues to grow, though at a slower rate than before.
New Jersey Counties By Population Change from 2020 to 2021
| County | 2020 Estimated Population | 2021 Estimated Population | % Change in Population From Year to Year |
|---|---|---|---|
| Ocean County | 638,824 | 648,998 | 1.6% |
| Warren County | 109,595 | 110,731 | 1% |
| Sussex County | 144,082 | 145,543 | 1% |
| Hunterdon County | 128,839 | 129,924 | 0.8% |
| Gloucester County | 302,607 | 304,477 | 0.6% |
| Cape May County | 95,077 | 95,661 | 0.6% |
| Burlington County | 461,862 | 464,269 | 0.5% |
| Morris County | 509,001 | 510,981 | 0.4% |
| Monmouth County | 643,163 | 645,354 | 0.3% |
| Salem County | 64,859 | 65,046 | 0.3% |
| Atlantic County | 274,191 | 274,966 | 0.3% |
| Somerset County | 345,014 | 345,647 | 0.2% |
| Camden County | 523,204 | 523,771 | 0.1% |
| Bergen County | 954,774 | 953,819 | -0.1% |
| Middlesex County | 861,908 | 860,807 | -0.1% |
| Cumberland County | 153,848 | 153,627 | -0.1% |
| Mercer County | 386,759 | 385,898 | -0.2% |
| Union County | 574,349 | 572,114 | -0.4% |
| Essex County | 862,032 | 854,917 | -0.8% |
| Passaic County | 523,100 | 518,117 | -1% |
| Hudson County | 722,655 | 702,463 | -2.8% |
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