Place profile

Sejong

Area, population and population density of Sejong, with reference dates, geographic scope, official sources and an outline preview.

Compare this place
Area
465 km²

Reference date:

Population
391,965

Reference date:

Population density
843 people/km²

Calculated from the population and area above; their reference dates may differ.

On a familiar scale
≈ 1.71 × Taipei City

The closest rung on the Taiwan reference ladder; see the sources below.

Land per resident
1,186 m² of land per resident

The inverse of population density, from the same area and population figures.

Outline of Sejong
The outline is fitted to this frame, not a map for measuring distances. Outlying islands may make the main landmass appear smaller.

Scope and definitions

Sejong Special Self-Governing City's full administrative territory. Sejong is South Korea's smallest metropolitan-level city by population among the six on this page and, like Seoul, holds special-city status rather than being an ordinary metropolitan city (광역시). Population is resident registration population (주민등록인구) as at 2025-12-31, from this ministry's own annual administrative-area-and-population report — a different series from the Statistics Korea register-based census (등록센서스) that the South Korea and Seoul pages use, though the two series are usually close. Area is this same report's official administrative-area figure at 2025-12-31, not a figure computed from the map outline. This ministry's own administrative-area total for South Korea (100,517.62 km² at 2025-12-31) differs by about 0.06% from the 100,459.9 km² cadastral figure the South Korea and Seoul pages use, a small gap between two different official area series rather than an error.

Average administrative density does not describe population distribution in every neighborhood. Compare population definitions and reference dates alongside the numbers.

Place guide

How should this Sejong profile be read?

Sejong Special Self-Governing City is the smallest of the metropolitan-level places added to this site in this batch: 464.99 km² and 391,965 people as at 2025-12-31.

A special city, not a metropolitan city

Sejong holds special self-governing city status, the same broad category as Seoul, rather than being one of Korea’s ordinary metropolitan cities (광역시). It was purpose-built from 2012 to house relocated central-government ministries, which explains why a city this size sits alongside much larger Busan, Incheon, Daegu, Daejeon and Ulsan in national administrative tables.

The comparatively low density, about 843 people per km², reflects both its recent founding and the mix of farmland still inside its administrative boundary.

Where the numbers come from

Both area and population are read from the Ministry of the Interior and Safety’s annual administrative-area-and-population report at 2025-12-31. Population is resident registration population (주민등록인구), a different series from the Statistics Korea register-based census used on the South Korea and Seoul pages.

Sejong has no offshore islands or coastal boundary questions, so its OpenStreetMap administrative relation was used directly for the outline, matching the official area within a fraction of one percent.

Questions people ask

About Sejong’s area and population

How big is Sejong?

Sejong covers 465 km² (reference date 2025-12-31). On the Taiwan reference ladder: ≈ 1.71 × Taipei City.

What is the population of Sejong?

391,965 as of 2025-12-31. The scope of that count is set out under “Scope and definitions” on this page.

What is the population density of Sejong?

About 843 people per km², derived from the area and population above, whose reference dates may differ. An administrative average does not describe how crowded any particular neighbourhood is.

What do these Sejong figures include?

Sejong Special Self-Governing City's full administrative territory. Sejong is South Korea's smallest metropolitan-level city by population among the six on this page and, like Seoul, holds special-city status rather than being an ordinary metropolitan city (광역시). Population is resident registration population (주민등록인구) as at 2025-12-31, from this ministry's own annual administrative-area-and-population report — a different series from the Statistics Korea register-based census (등록센서스) that the South Korea and Seoul pages use, though the two series are usually close. Area is this same report's official administrative-area figure at 2025-12-31, not a figure computed from the map outline. This ministry's own administrative-area total for South Korea (100,517.62 km² at 2025-12-31) differs by about 0.06% from the 100,459.9 km² cadastral figure the South Korea and Seoul pages use, a small gap between two different official area series rather than an error.

Data sources

Outline source: © OpenStreetMap contributors · ODbL · source feature

Read the methodology and data notes