South Plainfield, New Jersey demographics

South Plainfield, NJ demographics: median age 41.7; 44.0% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · South Plainfield borough, New Jersey · Incorporated borough · GEOID 3469390. The survey estimates a population of 24,473 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in South Plainfield is 41.7 years, with a 90% margin of error of 1.3 years. There are 8,351 households (±261). Age and household distributions show how these totals are composed; they do not establish which neighborhood suits a particular person.

Every count and share is an estimate. “±” is a 90% margin of error (MOE); pp means percentage points. Derived shares use the category count divided by the named universe. Aggregated category MOEs and percentage MOEs are approximate. A margin larger than half its estimate is flagged as low precision. Blank source uncertainty is shown as unavailable, never zero.

Age distribution and sex

City, state and U.S. estimates · ACS 2020–2024
Measure / survey universe	City estimate ± MOE	State estimate ± MOE	U.S. estimate ± MOE
Median age Total population · years	41.7 ±1.3	40.1 ±0.1	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 24,473
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
Under 18	5,121 ±477	20.9% ±1.9 pp	21.8%	22.0%
18–34	4,398 ±464	18.0% ±1.9 pp	21.3%	22.8%
35–64	10,196 ±630	41.7% ±2.6 pp	39.7%	38.0%
65 and older	4,758 ±486	19.4% ±2.0 pp	17.2%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 24,473
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
Male	12,244 ±365	50.0% ±1.5 pp	49.2%	49.5%
Female	12,229 ±362	50.0% ±1.5 pp	50.8%	50.5%

The age groups are mutually exclusive and cover the entire population. The sex categories follow this ACS table’s published classification; they are not a survey of gender identity.

Race and Hispanic origin

Race · B02001 · ACS 2020–2024 Total population: 24,473
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
White alone	12,349 ±893	50.5% ±3.6 pp	54.0%	61.0%
Black or African American alone	2,441 ±657	10.0% ±2.7 pp	12.8%	12.2%
American Indian and Alaska Native alone	216 ±164 · low precision	0.9% ±0.7 pp · low precision	0.6%	0.9%
Asian alone	5,217 ±851	21.3% ±3.5 pp	10.1%	6.0%
Native Hawaiian and Other Pacific Islander alone	0 ±26 · low precision	0.0% ±0.1 pp · low precision	0.0%	0.2%
Some other race alone	1,756 ±515	7.2% ±2.1 pp	10.1%	7.1%
Two or more races	2,494 ±538	10.2% ±2.2 pp	12.4%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 24,473
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
Not Hispanic or Latino	20,314 ±526	83.0% ±2.1 pp	77.5%	80.7%
Hispanic or Latino	4,159 ±537	17.0% ±2.2 pp	22.5%	19.3%

Hispanic origin and race are separate questions. People of Hispanic or Latino origin may be of any race and appear in both tables. Do not add the Hispanic share to race shares. Race alone and two-or-more-race groups are the mutually exclusive categories of the race table.

Household types, children and living alone

Household types · B11001 · ACS 2020–2024 Households: 8,351
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
Married-couple family	5,694 ±289	68.2% ±2.7 pp	49.8%	46.9%
Other family: male householder, no spouse present	372 ±125	4.5% ±1.5 pp	5.1%	5.1%
Other family: female householder, no spouse present	697 ±199	8.3% ±2.4 pp	12.9%	12.2%
Nonfamily: householder living alone	1,322 ±220	15.8% ±2.6 pp	26.4%	28.7%
Nonfamily: householder not living alone	266 ±124	3.2% ±1.5 pp	5.8%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 8,351
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
Households with people under 18	2,917 ±230	34.9% ±2.5 pp	31.2%	29.5%
Households without people under 18	5,434 ±384	65.1% ±4.1 pp	68.8%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 8,351
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
One-person nonfamily households	1,322 ±220	15.8% ±2.6 pp	26.4%	28.7%
Two-person households	2,658 ±329	31.8% ±3.8 pp	31.1%	33.8%
Three-person households	1,610 ±197	19.3% ±2.3 pp	17.1%	15.3%
Four-person households	1,842 ±220	22.1% ±2.5 pp	15.2%	12.6%
Five-person households	619 ±192	7.4% ±2.3 pp	6.3%	5.9%
Six-person households	145 ±92 · low precision	1.7% ±1.1 pp · low precision	2.3%	2.2%
Seven or more people	155 ±88 · low precision	1.9% ±1.1 pp · low precision	1.6%	1.4%

A family household contains related people under the Census definition. A nonfamily household can contain one person or unrelated people sharing a home. Households with children can also appear in the household-type and size tables, so those tables must not be added together. Household estimates exclude people living in group quarters from the household universe.

Nativity and languages spoken at home

Nativity · B05002 · ACS 2020–2024 Total population: 24,473
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
Native	18,626 ±565	76.1% ±2.3 pp	76.1%	85.9%
Foreign born	5,847 ±564	23.9% ±2.3 pp	23.9%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 22,941
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
English only	15,025 ±793	65.5% ±3.4 pp	66.9%	77.7%
Spanish	2,720 ±519	11.9% ±2.3 pp	17.2%	13.6%
French, Haitian, or Cajun	73 ±53 · low precision	0.3% ±0.2 pp · low precision	1.1%	0.7%
German or other West Germanic	76 ±71 · low precision	0.3% ±0.3 pp · low precision	0.4%	0.5%
Russian, Polish, or other Slavic	179 ±137 · low precision	0.8% ±0.6 pp · low precision	1.7%	0.7%
Other Indo-European	2,320 ±528	10.1% ±2.3 pp	5.6%	2.0%
Korean	109 ±83 · low precision	0.5% ±0.4 pp · low precision	0.9%	0.3%
Chinese, including Mandarin and Cantonese	239 ±133 · low precision	1.0% ±0.6 pp · low precision	1.5%	1.1%
Vietnamese	467 ±236 · low precision	2.0% ±1.0 pp · low precision	0.2%	0.5%
Tagalog, including Filipino	357 ±265 · low precision	1.6% ±1.2 pp · low precision	0.9%	0.6%
Other Asian and Pacific Island	931 ±492 · low precision	4.1% ±2.1 pp · low precision	1.6%	1.1%
Arabic	144 ±84 · low precision	0.6% ±0.4 pp · low precision	0.9%	0.5%
Other and unspecified	301 ±282 · low precision	1.3% ±1.2 pp · low precision	1.1%	0.8%

Foreign born means not a U.S. citizen at birth; it includes naturalized citizens. Language categories describe speech at home among people age five and older. A language other than English at home does not establish that someone cannot speak English. This city page uses the published C16001 summary categories because the more detailed B16001 table does not provide these city records in this release.

Educational attainment

Highest completed education · B15003 · ACS 2020–2024 Population age 25 and older: 17,605
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
Less than high school graduate	1,313 ±370	7.5% ±2.1 pp	9.3%	10.4%
High school graduate or equivalency	4,158 ±479	23.6% ±2.7 pp	25.3%	26.0%
Some college, no degree	3,061 ±408	17.4% ±2.3 pp	15.0%	19.1%
Associate’s degree	1,334 ±263	7.6% ±1.5 pp	6.7%	8.8%
Bachelor’s degree	4,613 ±555	26.2% ±3.1 pp	26.1%	21.6%
Graduate or professional degree	3,126 ±489	17.8% ±2.8 pp	17.6%	14.1%

The denominator excludes residents under 25. Each person is counted in the highest attainment category they completed. This table does not measure the quality of local schools or the education level of every current student.

Residence one year earlier

Geographic mobility · B07003 · ACS 2020–2024 Population age 1 and older: 24,371
Category	Count ± MOE	Share ± MOE (pp)	New Jersey	U.S.
Same house	22,879 ±473	93.9% ±1.9 pp	90.4%	87.7%
Moved within same county	580 ±313 · low precision	2.4% ±1.3 pp · low precision	4.4%	6.3%
Moved from a different county in the same state	617 ±248	2.5% ±1.0 pp	2.5%	3.1%
Moved from a different state	226 ±187 · low precision	0.9% ±0.8 pp · low precision	1.8%	2.3%
Moved from abroad	69 ±51 · low precision	0.3% ±0.2 pp · low precision	0.8%	0.6%

These are respondents’ residence patterns one year before their survey response, pooled across the five-year window. They are not a net migration count for 2025. A person can move to a different house within the same city or county; moves within the same county should not automatically be interpreted as new arrivals to the city.

Health insurance, internet access and veterans

3.2% of South Plainfield residents (±1.0 percentage points) had no health insurance coverage when surveyed, compared with 7.5% in New Jersey and 8.4% nationally. 95.5% of households subscribe to broadband of any type, including cellular data plans. A subscription is not the same as available service: the FCC National Broadband Map shows providers at a specific address.

City, state and U.S. shares · ACS 2020–2024
Measure	South Plainfield	New Jersey	U.S.	Compared with New Jersey
People without health insurance Civilian noninstitutionalized population	3.2% ±1.0 pp	7.5%	8.4%	Lower
Households with a broadband subscription Households	95.5% ±1.4 pp	92.8%	91.0%	Higher
Veterans Civilian population age 18 and older	2.9% ±0.7 pp	3.7%	6.2%	Lower

Reading and reusing the estimates

The Census table links above lead to the original detailed tables. Counts, source universes and uncertainty are retained in the source observation download for South Plainfield . Compare these figures with the same survey window; do not compare one city’s five-year estimate with another city’s annual estimate as though they measured the same period. For methods, see uncertainty and denominator calculations.

Read South Plainfield housing and cost context or return to the city profile.