Seneca, South Carolina demographics

Seneca, SC demographics: median age 39.6; 29.1% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · Seneca city, South Carolina · Incorporated city · GEOID 4565095. The survey estimates a population of 8,993 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in Seneca is 39.6 years, with a 90% margin of error of 5.2 years. There are 4,082 households (±360). 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	39.6 ±5.2	40.2 ±0.2	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 8,993
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
Under 18	1,665 ±366	18.5% ±4.1 pp	21.4%	22.0%
18–34	2,219 ±462	24.7% ±5.1 pp	22.0%	22.8%
35–64	3,274 ±483	36.4% ±5.4 pp	37.7%	38.0%
65 and older	1,835 ±282	20.4% ±3.1 pp	18.9%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 8,993
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
Male	4,039 ±296	44.9% ±3.3 pp	48.7%	49.5%
Female	4,954 ±297	55.1% ±3.3 pp	51.3%	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: 8,993
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
White alone	6,605 ±511	73.4% ±5.6 pp	63.3%	61.0%
Black or African American alone	1,578 ±509	17.5% ±5.7 pp	24.8%	12.2%
American Indian and Alaska Native alone	69 ±65 · low precision	0.8% ±0.7 pp · low precision	0.4%	0.9%
Asian alone	72 ±61 · low precision	0.8% ±0.7 pp · low precision	1.8%	6.0%
Native Hawaiian and Other Pacific Islander alone	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.1%	0.2%
Some other race alone	240 ±155 · low precision	2.7% ±1.7 pp · low precision	2.8%	7.1%
Two or more races	429 ±231 · low precision	4.8% ±2.6 pp · low precision	6.8%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 8,993
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
Not Hispanic or Latino	8,421 ±274	93.6% ±2.9 pp	92.6%	80.7%
Hispanic or Latino	572 ±260	6.4% ±2.9 pp	7.4%	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: 4,082
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
Married-couple family	1,563 ±236	38.3% ±4.7 pp	47.1%	46.9%
Other family: male householder, no spouse present	207 ±148 · low precision	5.1% ±3.6 pp · low precision	4.5%	5.1%
Other family: female householder, no spouse present	776 ±204	19.0% ±4.7 pp	13.4%	12.2%
Nonfamily: householder living alone	1,459 ±405	35.7% ±9.4 pp	29.2%	28.7%
Nonfamily: householder not living alone	77 ±56 · low precision	1.9% ±1.4 pp · low precision	5.8%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 4,082
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
Households with people under 18	1,123 ±223	27.5% ±4.9 pp	28.6%	29.5%
Households without people under 18	2,959 ±479	72.5% ±9.8 pp	71.4%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 4,082
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
One-person nonfamily households	1,459 ±405	35.7% ±9.4 pp	29.2%	28.7%
Two-person households	1,342 ±297	32.9% ±6.7 pp	36.3%	33.8%
Three-person households	636 ±220	15.6% ±5.2 pp	15.4%	15.3%
Four-person households	396 ±166	9.7% ±4.0 pp	11.6%	12.6%
Five-person households	174 ±102 · low precision	4.3% ±2.5 pp · low precision	5.0%	5.9%
Six-person households	75 ±99 · low precision	1.8% ±2.4 pp · low precision	1.7%	2.2%
Seven or more people	0 ±28 · low precision	0.0% ±0.7 pp · low precision	0.9%	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: 8,993
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
Native	8,758 ±139	97.4% ±1.3 pp	94.2%	85.9%
Foreign born	235 ±111	2.6% ±1.2 pp	5.8%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 8,281
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
English only	7,976 ±284	96.3% ±2.1 pp	91.6%	77.7%
Spanish	237 ±156 · low precision	2.9% ±1.9 pp · low precision	5.3%	13.6%
French, Haitian, or Cajun	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.3%	0.7%
German or other West Germanic	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.3%	0.5%
Russian, Polish, or other Slavic	3 ±6 · low precision	0.0% ±0.1 pp · low precision	0.4%	0.7%
Other Indo-European	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.8%	2.0%
Korean	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.1%	0.3%
Chinese, including Mandarin and Cantonese	45 ±56 · low precision	0.5% ±0.7 pp · low precision	0.2%	1.1%
Vietnamese	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.2%	0.5%
Tagalog, including Filipino	20 ±31 · low precision	0.2% ±0.4 pp · low precision	0.2%	0.6%
Other Asian and Pacific Island	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.4%	1.1%
Arabic	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.1%	0.5%
Other and unspecified	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.3%	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: 6,735
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
Less than high school graduate	884 ±285	13.1% ±4.1 pp	9.9%	10.4%
High school graduate or equivalency	1,687 ±376	25.0% ±5.3 pp	28.2%	26.0%
Some college, no degree	1,432 ±379	21.3% ±5.4 pp	19.8%	19.1%
Associate’s degree	769 ±261	11.4% ±3.8 pp	10.0%	8.8%
Bachelor’s degree	1,288 ±354	19.1% ±5.1 pp	19.8%	21.6%
Graduate or professional degree	675 ±198	10.0% ±2.9 pp	12.3%	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: 8,957
Category	Count ± MOE	Share ± MOE (pp)	South Carolina	U.S.
Same house	7,143 ±549	79.7% ±6.1 pp	87.2%	87.7%
Moved within same county	1,047 ±496	11.7% ±5.5 pp	5.5%	6.3%
Moved from a different county in the same state	135 ±110 · low precision	1.5% ±1.2 pp · low precision	3.1%	3.1%
Moved from a different state	597 ±285	6.7% ±3.2 pp	3.7%	2.3%
Moved from abroad	35 ±32 · low precision	0.4% ±0.4 pp · low precision	0.4%	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

11.4% of Seneca residents (±3.9 percentage points) had no health insurance coverage when surveyed, compared with 9.6% in South Carolina and 8.4% nationally. 86.9% 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	Seneca	South Carolina	U.S.	Compared with South Carolina
People without health insurance Civilian noninstitutionalized population	11.4% ±3.9 pp	9.6%	8.4%	Not statistically different
Households with a broadband subscription Households	86.9% ±2.3 pp	88.8%	91.0%	Not statistically different
Veterans Civilian population age 18 and older	5.2% ±1.8 pp	8.3%	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 Seneca . 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 Seneca housing and cost context or return to the city profile.