Capital Cities · A Geography of Definitions
Paris is not small.
It is just drawn small.
“Paris has 2 million people; London has 9.” True — and meaningless. Administrative “Paris” is the bit inside the Périphérique: 105 km², one-fifteenth the size of Greater London. Compare like with like, and the league table changes completely. Here are ten great world cities measured five different ways.
01Greater Paris vs “Paris”: what the border actually captures
This is the chart that settles it. Every pale bar is the real city — its full metropolitan population, drawn to scale. The dark segment is the slice that happens to live inside the official boundary. London's border (1965) was drawn around the real city. Istanbul's (2012) and Beijing's are drawn far beyond it. Paris's was frozen at its 1860 walls — so “Paris” captures barely a seventh of the city that actually exists.
02Pick your definition, pick your winner
The same ten cities, ranked under five definitions of “size”. Watch Paris move from dead last to the middle of the pack — and watch the “giant” Chinese municipalities shrink once you realise they are drawn the size of small countries.
03The rings: population within 5–50 km of the centre
The definition-proof method: draw circles of equal radius around each city's historic centre and count everyone inside, using the EU's GHS-POP satellite-based population grid (2025 epoch). No borders involved. Click a city in the legend to isolate it.
04One city, five sizes
Each city's rank (1–10) under each definition. Administrative boundaries are the outlier, not the rule: on every other measure the same broad hierarchy appears — and Paris sits comfortably among the giants.
05Why the confusion persists
Every country draws its cities differently. France froze Paris at its 1860 walls; the “real” city spilled over a century ago. China does the opposite: Beijing municipality covers 16,410 km² — an area the size of half of Belgium, including farms and mountains two hours from Tiananmen. Turkey made Istanbul province and city legally identical in 2012. The UK and Japan happen to sit in the middle, with Greater London and Tokyo's 23 wards roughly hugging the dense urban core — which is why they look “normal” and Paris looks tiny.
So “city proper” population mostly measures the ambition of 19th- and 20th-century boundary commissions, not the size of cities. Any honest comparison needs a border-free yardstick — commuting basins, fixed-radius circles, or the continuous built-up fabric visible from space.
06Method & sources
The five measures
City proper — population of the legal administrative unit (commune of Paris, Greater London, NYC's five boroughs, Tokyo's 23 wards, the Chinese municipalities, Seoul Special City, Moscow federal city, City of Los Angeles, Istanbul province). Latest official estimates, 2023–2025.
Metropolitan area / FUA — city plus commuting belt (INSEE aire d'attraction, ONS/OECD metro, US MSA, Greater Tokyo, Seoul Capital Region, etc.). Rounded, latest available.
Population within 30 km — computed for this page from the European Commission JRC GHS-POP R2023A grid (2025 epoch, 30″ resolution): sum of all grid cells whose centre lies within 30 km of the historic centre (Notre-Dame, Charing Cross, City Hall NYC, Tokyo Station, Tiananmen, People's Square, Seoul City Hall, the Kremlin, LA City Hall, Sultanahmet). Model-based estimates; dense Chinese cores may be somewhat overstated.
Built-up urban area — Demographia World Urban Areas, 20th edition (2025): the continuously built-up agglomeration, ignoring all administrative lines. Shanghai figure covers the merged Shanghai–Suzhou–Wuxi–Changzhou area.
Metro GDP — nominal USD, Wikipedia, List of metropolitan areas by GDP (official statistical offices; mixed years 2022–2025, unadjusted).
Caveats
All figures rounded to 0.1M / $1bn; different measures come from different years and statistical traditions, which is precisely the point of the page. Treat gaps of less than ~10% as ties.