Baltimore County, Maryland

A county in Maryland, ranked 3 of 24 by population.

CountyFIPS 24005

Within Maryland

Baltimore County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Towson, the county seat, located via the 2025 Census Gazetteer.

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Population: 847,650; -5,700 (-0.7%) since 2020
Land area: 598.4; square miles. A further 12.2% of the total area is water
Population density: 1,417; people per square mile, computed rather than published
County seat: Towson; Seat of county government.
Established: 1659; 366 years ago
Largest city: Not available; No incorporated place lies within this county.

Satellite view

Aerial imagery of Baltimore County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Baltimore County, Maryland from the USGS National Map, with its boundary outlined — Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 688 by 800 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Baltimore County ranks

Position among the 24 counties of Maryland, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

Measure	Value	In Maryland	Nationally
Population	847,650	3rd of 24	75th of 3,144
Land area	598.4 sq mi	3rd of 24	1,627th of 3,144
Population density	1,417 per sq mi	5th of 24	115th of 3,144
Median household income	$91,768	13th of 24	272nd of 3,143

Full data for Baltimore County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
Measure	Value	Source and vintage
Population	847,650	Vintage 2025 Population Estimates
Population in 2020	853,350	Vintage 2025 Population Estimates
2020 estimates base?	854,513	Vintage 2025 Population Estimates
Land area	598.4 sq mi	2025 Gazetteer Files
Water area	83.4 sq mi	2025 Gazetteer Files
Total area	681.7 sq mi	2025 Gazetteer Files
Population density?	1,417 per sq mi	Computed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income	$91,768	American Community Survey 2020-2024 5-Year Estimates
Median home value	$349,300	American Community Survey 2020-2024 5-Year Estimates
Median age	39.7	American Community Survey 2020-2024 5-Year Estimates
Households	332,801	American Community Survey 2020-2024 5-Year Estimates
Housing units	350,821	American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths: +490; 9,084 births, 8,594 deaths
Net migration: -1,300; More people moved out than moved in.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 7 areas bordering Baltimore County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering area	State	Shared border	Population
Harford County	Maryland	48 mi	266,446
Carroll County	Maryland	37 mi	176,677
Baltimore city	Maryland	33 mi	569,997
Howard County	Maryland	20 mi	339,183
Anne Arundel County	Maryland	16 mi	603,380
York County	Pennsylvania	12 mi	473,197
Kent County	Maryland	7.6 mi	19,565

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

Side by side

All 24 counties of Maryland

Open the interactive Maryland county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.