Frankfort: Demographics & People
Frankfort is home to 20,651 people, in 6,789 households. Population grew 1.1% from 20,417 (2022) to 20,651 (2024). Median age 42.2 years. (3.1y older than Will County; 4.5y older than Illinois). Children under 18 are 28% of the population. Population is 75% White (non-Hispanic) and 10% Black. The community is somewhat diverse (Simpson index 0.33). 83% of households are family-led. County is losing 127,111 residents per year (2022-2023). County health: 33% adult obesity, 12% smoke.
- 3.0 people per household (vs Illinois avg 2.5).
- 17% non-family households (singles, roommates) (vs Illinois 38%).
- 82 dependents per 100 working-age (youth + seniors / 18-64) (vs Illinois 64).
Population & Trend
Population grew 1.1% from 20,417 (2022) to 20,651 (2024) — about 1.9× the recent U.S. annual rate of ~0.6%/yr. Estimated 2026 population: ~20,889 (extrapolated at 0.6%/yr trend). Census Bureau Vintage estimate: 21,210.
| Census data vintage | 2024 |
|---|---|
| Population | 5,275,541 people |
| Annual growth rate · Population change | 1.1% |
| Annual growth rate · Population (2022) | 20,417 |
| Annual growth rate · Population (2024) | 20,651 |
| Annual growth rate · Population growing | Yes |
| Annual growth rate · Trend category | growing |
| Population | 20,651 people (vs Illinois 39,460) |
| Population Estimate | 21,210 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 42.2y is 3.3 years older than the U.S. median (38.9y). Children under 18 make up 28% — above the U.S. share of ~22%.
| Age Summary · Median age | 42.2 years (vs Illinois 37.7y) |
|---|---|
| Age Summary · Children Pct | 28.5% |
| Age Summary · Character | established |
| Age Summary · Total Pop | 20,651 |
| Age Summary · Under 18 | 5,878 |
| Age Summary · 18 To 34 | 2,647.0× |
| Age Summary · 35 To 64 | 8,673.0× |
| Age Summary · 65 Plus | 3,453 |
| Population under 18 | 5,878 |
| Median age | 42.2 years (vs Illinois 37.7y) |
Sources: Census ACS 5-Year 2024 — place-level B01001 query · Census ACS 5-Year 2023 · Refreshed 2026-04-29
Race, Ethnicity & Diversity
Of 20,651 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.33 (0 = single group, 1 = perfectly even distribution); this is read as somewhat diverse.
| White residents | 16,198 |
|---|---|
| Black residents | 2,229 |
| Asian residents | 533 |
| Hispanic or Latino residents | 1,132 |
| Diversity Index · Diversity index (Simpson) | 33.4% |
| Diversity Index · Diversity label | somewhat diverse |
| Diversity Index · Groups counted | 4 |
| Diversity Index · Largest group share | 80.6% |
| Asian population | 2.6% (vs Illinois 6.1%) |
| Black population | 10.2% (vs Illinois 9.3%) |
| Hispanic or Latino population | 7.0% (vs Illinois 17.6%) |
| White (non-Hispanic) population | 75.1% (vs Illinois 54.8%) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Ancestry
Self-reported ancestry from Census ACS — what residents report as their ethnic origin, separate from race. Counts can exceed population because people can list multiple ancestries.
Top (8)
Citizenship & Origin
Where residents were born and their citizenship status (Census ACS). 0.8% are foreign-born — below the U.S. average of 13.9%. 6% have naturalized to U.S. citizenship.
| Residents born in this state | 15,549 |
|---|---|
| Residents born in another state | 3,658 |
| Share born in this state | 75.3% |
| Share born in another state | 24.7% |
| Native-born U.S. citizens | 17.7% |
| Foreign-born residents | 0.8% |
| Naturalized citizens | 6.2% |
| Total foreign-born residents | 1,432 |
| From Europe | 401 |
| From Africa | 355 |
Households & Family Composition
6,789 households. Averaging 3.1 people each — larger than the U.S. average of 2.5. 83% are family households — above the U.S. share of ~65%. Of 5,497 families, 45% are married couples with children.
| Children under 18 | 6,031 |
|---|---|
| Total families | 5,497 |
| Married couples with children | 2,468 |
| Single-parent households | 98 |
| Average household size | 3.08 |
| Women who gave birth (past year) | 7.6% |
| Grandparents living with grandchildren | 239 |
| Grandparents responsible for grandchildren | 69 |
| Family households | 5,638 households (vs Illinois 9,709) |
| Households that are families | 83.0% (vs Illinois 62.4%) |
| Total households | 6,789 households (vs Illinois 14,867) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Residential Stability & Migration
How long residents have lived here and where they came from. 6.8% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is losing 127,111 residents per year on net (IRS migration data).
| Moved within the county (past year) | 6.8% |
|---|---|
| Migration · People moving in (annual) | 4,217,303 |
| Migration · People moving out (annual) | 4,344,414 |
| Migration · Net migration (in − out) | -127,111 |
| Migration · Year | 2022-2023 |
Sources: IRS SOI Migration 2021-2022 · Refreshed 2026-04-12
Disability
Census ACS measures self-reported functional limitations — vision, hearing, mobility, cognitive, self-care, or independent-living. The U.S. baseline disability rate is about 12–13%; rates trend higher with median age.
| Residents with a disability | 760 |
|---|---|
| Disability rate | 3.8% |
Group Quarters
Group quarters are non-household living arrangements counted by the Census — college dormitories, nursing homes, military barracks, group homes, correctional facilities, and similar institutional or shared housing. 143 residents live in group quarters (0.7% of population).
| Living in group quarters | 143 |
|---|
Other
| Congressional District · District | 1 |
|---|---|
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 17031 |
| Cdc Birth Rate · State Fips | 17 |
| Cdc Birth Rate · County Fips | 031 |
| Cdc Birth Rate · County | Cook |
| Cdc Birth Rate · Birth Rate | 15.3% |
| Cdc Birth Rate · Lower Ci | 14.90 |
| Cdc Birth Rate · Upper Ci | 15.70 |
| Cdc Mortality · Fips | 17031 |
| Cdc Mortality · County | Cook County |
| Cdc Mortality · Urban Rural | Large central metro |
| Cdc Mortality · Total Deaths 2020 2023 | 165,505 |
| Cdc Vaccination · Fips | 17031 |
| Cdc Vaccination · County | Cook County |
| Cdc Vaccination · Dose1 Pop Pct | 84.0% |
| Cdc Vaccination · Series Complete Pct | 75.2% |
| Cdc Vaccination · Booster Pct | 58.5% |
| Cdc Vaccination · Population 2019 | 5,150,233 |
| Cdc Vaccination · Metro Status | Metro |
| Family Score · Score | 7.60 |
| Family Score · Schools | 11 |
| Family Score · Childcare Centers | 2 |
| Family Score · Youth Sports Orgs | 1 |
| Family Score · Children Pct | 28.5% |
| Family Score · Rating | excellent |
| Town Summary · Key Facts | population 20,651, growing, established, affluent, white collar |
| Town Summary · Population | 20,651 people (vs Illinois 39,460) |
| Town Summary · County | Cook County |
Sources: NCES school congressional district assignment · federal dataset cascade