Daily Dose · Maps / Oct 12, 2026 / Population · Half-World Circle
Half of us fit in this circle
In 2013 a Reddit mapmaker noticed that more than half of humanity lives inside one circle over Asia. Since then, people have computed the smallest such circle. It is centred in the mountains of northern Yunnan, China, and covers less than a fourteenth of the globe.
3,386km
Radius of the smallest circle on Earth that contains half of all people (Arthur, 2024, using 2020-era gridded population data).
6.9%of Earth's surface, about 35 million km², lies inside that circle (our calculation).
4,968 kmfrom the circle's centre to humanity's mean centre, out in the Arabian Desert (our calculation).
smallest circle holding 50% of peoplecity insidecity outsidedense belts (schematic)mean centre of population
Azimuthal equidistant projection centred on 28.4°N 100.6°E, so every distance from the red dot is true to scale and the circle stays a circle. Coastlines are hand-simplified. Outer edge is 6,000 km.
01 · On the knife edge
Karachi is just inside. Tokyo is just outside.
Great-circle distance from the circle's centre to 18 big cities. Anything left of the red line is in the half-world circle.
Our calculations on a spherical Earth (R = 6,371 km). Osaka sits 24 km inside the edge and Karachi 32 km. Tokyo is 361 km outside and Jakarta 515 km. The circle comes from a gridded dataset, so treat cities within a few dozen km of the edge as borderline.
02 · Three tries at one circle
The circle keeps getting smaller as the method gets sharper
The first version was drawn by eye on a flat map. Later versions searched the globe on population grids for the smallest circle that still holds half of all people.
The 2013 radius is approximate. Quah's 2015 search used a 100 km grid; Arthur's uses SEDAC's 15-arc-minute (~30 km) grid. The differences come from method and data, so this is not a trend over time. A 2022 variant by cartographer Alasdair Rae, centred on Yuxi, Yunnan, was reported to hold 4.32 billion people (55%).
03 · Who lives inside
Eight countries, nearly half the world
The circle is dominated by two giants. India and China alone hold 35% of humanity, and Indonesia mostly falls outside.
Populations: UN World Population Prospects 2024, 2025 estimates. "Inside" tags are approximate, based on our distance checks for each country's major cities. Most of Java (Jakarta, Surabaya) lies beyond the edge, while Sumatra's north (Medan, 2,762 km) is inside.
04 · Two centres of humanity
The average human lives in a desert where almost nobody lives
If you average everyone's position, you land at 22.1°N 51.4°E in the Arabian Desert, between the population masses of Asia, Europe and Africa. The circle's centre instead sits on the people themselves.
Arthur measures the spread around the mean centre with the Bachi standard distance, which comes to 6,583 km. The circle radius is about half that, at 3,386 km, because it is a spatial median: it follows where most people are rather than the pull of distant outliers.
05 · The scale strip
Every territory has its own half-circle
The same idea works at any scale. The smallest circle holding half a territory's people is a measure of how concentrated it is (Arthur 2024, 2020 data, log scale).
Half of Mongolia's people live within 34 km of one point, Ulaanbaatar. Great Britain needs 132 km and the continental US 949 km. Humanity as a whole needs 3,386 km.
06 · Circles that move
A shrinking circle means a country is concentrating
From 2000 to 2020, Mongolia's half-circle shrank as people moved to Ulaanbaatar, while the US circle widened. The two panels use separate scales.
227 km in 2000 → 34 km in 2020: the largest drop of any country in the study.
863 km → 949 km: the largest rise of any country, as growth tilted south and west.
Why it matters · what to notice on the map
The map is lopsided on purpose
Half of the world's people live in about 7% of its surface. Monsoon river plains such as the Ganges, Yangtze and Pearl, along with Java and the North China Plain, have fed dense populations for millennia. Today that also concentrates exposure to heat, floods, sea-level rise and food-price shocks in one part of the globe.
The red dot sits in empty mountains. The centre of half of humanity has few people nearby, because the circle balances India against eastern China.
Large parts of the circle are close to empty: the Tibetan Plateau, the Gobi and southern Siberia. Only a few river plains carry most of the weight.
The green dot in Arabia shows why an average can mislead: almost nobody lives at humanity's mean centre.
The edge splits nations. Osaka is in and Tokyo is out; Medan is in and Jakarta is out; Karachi only just makes it.
Sources & notes
Arthur, R. (2024). "Valeriepieris circles for spatial data analysis." Geographical Analysis 56: 514–529 (preprint arXiv:2307.16728, 2023). Global circle radius 3,386 km, centre 28.375°N 100.625°E; mean centre of population 22.125°N 51.375°E; Bachi standard distance 6,583 km; VP radii for Mongolia, Great Britain and the continental US, 2000–2020.
CIESIN, Columbia University (2018). Gridded Population of the World, v4. NASA SEDAC. The population grid used by Arthur.
Quah, D. (2015). "The world's tightest cluster of people." LSE blog, 16 Dec 2015. A 3,300 km circle near Mong Khet, Myanmar, computed on a 100 km grid; reports that the original circle was ~4,000 km.
Myers, K. (Reddit user "Valeriepieris") (2013). r/MapPorn post that introduced the original circle.
Rae, A. (2022). Yuxi-centred circle with 4.32 billion people (55%), as summarised in Wikipedia, "Valeriepieris circle."
United Nations DESA (2024). World Population Prospects 2024, 2025 estimates (via INED): world 8,232M; India 1,464M; China 1,416M; Indonesia 286M; Pakistan 255M; Bangladesh 176M; Japan 123M; Philippines 117M; Vietnam 102M.
Arthur (2024) attributes Mongolia's shrinking radius to rural-to-urban migration, citing IOM et al. (2021).
Derived / illustrative · These are Daily Dose calculations on a spherical Earth (R = 6,371 km): the surface shares (6.6%, 6.9%, ≈9.5%), 35 million km², every city distance, the 4,968 km between centres, and the country shares (35.0%, 47.9%). The country "inside/outside" tags are approximate. The density belts on the map are schematic, not data. The coastlines are hand-simplified, and the Quah 2015 centre is placed approximately.