Mercer County Demographics

A map of Mercer County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	164,891	168,580	42.7%	43.5%
Hispanic	89,099	84,177	23.1%	21.7%
Black	69,099	72,364	17.9%	18.7%
Asian	47,553	48,330	12.3%	12.5%
Multiracial	13,059	11,477	3.4%	3.0%
Native American/Other	2,163	2,412	0.6%	0.6%

Mercer County, New Jersey has an estimated population of 385,864, a less than 1% change from the 387,340 recorded in the 2020 Census. The population is 42.7% White, 23.1% Hispanic, 17.9% Black, 12.3% Asian, 3.4% Multiracial, and 0.6% Native American/Other. This demographic dot map shows the population of Mercer County, with one dot drawn for each person counted by the Census, color-coded by race.

Mercer is about as racially diverse as it was in the 2020 Census. It is considerably more diverse than New Jersey overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In Mercer County, that probability was 71.2% in 2020 and 71.6% in the most recent ACS estimates.

Mercer County is ranked the 12th most populous county in New Jersey, out of 21 counties. Mercer County was ranked the 12th most populous county in the 2020 Census.

Mercer County's White Population

164,891 residents of Mercer County, or 42.7% of the population, identify as White. The share of White residents in Mercer County is lower than in New Jersey overall, where 50.9% of the population is White. Mercer County ranks 15th statewide in terms of White residents as a share of the population, out of 21 counties.

Since the 2020 Census, Mercer County's White population has declined by an estimated 2.2%. White residents' share of Mercer County's population has decreased from 43.5% to 42.7%.

Mercer County is more White than neighboring Middlesex County (37.5% White). Mercer County is less White than neighboring Somerset County (49.3% White), Hunterdon County (79.9% White), Burlington County (62.4% White), and Bucks County (79.9% White).

Mercer County's Black Population

69,099 residents of Mercer County, or 17.9% of the population, identify as Black. The share of Black residents in Mercer County is higher than in New Jersey overall, where 12.2% of the population is Black. Mercer County ranks 3rd statewide in terms of Black residents as a share of the population, out of 21 counties.

Since the 2020 Census, Mercer County's Black population has declined by an estimated 4.5%. Black residents' share of Mercer County's population has decreased from 18.7% to 17.9%.

Mercer County is more Black than neighboring Somerset County (9.3% Black), Middlesex County (9.7% Black), Hunterdon County (2.4% Black), Burlington County (15.8% Black), and Bucks County (3.7% Black).

Mercer County's Asian Population

47,553 residents of Mercer County, or 12.3% of the population, identify as Asian. The share of Asian residents in Mercer County is slightly higher than in New Jersey overall, where 10% of the population is Asian. Mercer County ranks 5th statewide in terms of Asian residents as a share of the population, out of 21 counties.

Since the 2020 Census, Mercer County's Asian population has declined by an estimated 1.6%. Asian residents' share of Mercer County's population has remained roughly unchanged at 12.3%.

Mercer County is more Asian than neighboring Hunterdon County (4.9% Asian), Burlington County (5.8% Asian), and Bucks County (5% Asian). Mercer County is less Asian than neighboring Somerset County (19.6% Asian), and Middlesex County (25.4% Asian).

Mercer County's Hispanic Population

89,099 residents of Mercer County, or 23.1% of the population, identify as Hispanic. The share of Hispanic residents in Mercer County is comparable to the share in New Jersey overall, where 22.5% of the population is Hispanic. Mercer County ranks 7th statewide in terms of Hispanic residents as a share of the population, out of 21 counties.

Since the 2020 Census, Mercer County's Hispanic population has grown by an estimated 5.8%. Hispanic residents' share of Mercer County's population has increased from 21.7% to 23.1%.

Mercer County is more Hispanic than neighboring Somerset County (17.6% Hispanic), Hunterdon County (9.3% Hispanic), Burlington County (9.6% Hispanic), and Bucks County (6.6% Hispanic). Mercer County is less Hispanic than neighboring Middlesex County (23.6% Hispanic).

Mercer County's Native American/Other Population

2,163 residents of Mercer County, or 0.6% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Mercer County is comparable to the share in New Jersey overall, where 0.9% of the population is Native American/Other. Mercer County ranks 15th statewide in terms of Native American/Other residents as a share of the population, out of 21 counties.

Since the 2020 Census, Mercer County's Native American/Other population has declined by an estimated 10.3%. Native American/Other residents' share of Mercer County's population has remained roughly unchanged at 0.6%.

Mercer County is more Native American/Other than neighboring Hunterdon County (0.5% Native American/Other). Mercer County is less Native American/Other than neighboring Somerset County (0.7% Native American/Other), Middlesex County (0.9% Native American/Other), Burlington County (0.8% Native American/Other), and Bucks County (0.8% Native American/Other).

Mercer County's Multiracial Population

13,059 residents of Mercer County, or 3.4% of the population, identify as Multiracial. The share of Multiracial residents in Mercer County is comparable to the share in New Jersey overall, where 3.5% of the population is Multiracial. Mercer County ranks 16th statewide in terms of Multiracial residents as a share of the population, out of 21 counties.

Since the 2020 Census, Mercer County's Multiracial population has grown by an estimated 13.8%. Multiracial residents' share of Mercer County's population has remained roughly unchanged at 3.4%.

Mercer County is more Multiracial than neighboring Middlesex County (2.9% Multiracial), and Hunterdon County (3% Multiracial). Mercer County is less Multiracial than neighboring Somerset County (3.6% Multiracial), Burlington County (5.6% Multiracial), and Bucks County (4% Multiracial).

Sources: Most recent population estimates are from the 2020-2024 American Community Survey 5-Year Estimates. 2020 population counts and map data are from 2020 Census State Redistricting Data. Geographic data are from Census TIGER/Line Shapefiles.