Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
230,000,000
people
How to estimate it
Fermi’s official “Napkin math”
The line runs across the top of Australia and South Africa, and right through São Paulo. So it's Australia, southern Africa and the bottom of South America. How many people is that? Add it up piece by piece.
- Australia and New Zealand
- ~30,000,000
- South Africa and its neighbors
- + 70,000,000
- Argentina, Chile and southern Brazil
- + 120,000,000
- 30M + 70M + 120M
- ≈ 220,000,000
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- Southern Africa: South Africa, Lesotho, Eswatini, southern Mozambique, Botswana, Namibia and Madagascar
- ≈ 75,000,000
- Argentina, Chile, Paraguay and Uruguay, minus their far north
- ≈ 72,000,000
- Southern Brazil: most of São Paulo state, Paraná, Santa Catarina, Rio Grande do Sul
- ≈ 50,000,000
- Australia and New Zealand, minus tropical northern Australia
- ≈ 32,000,000
- 75M + 72M + 50M + 32M
- ≈ 230,000,000
Reference cited by Fermi: UN World Population Prospects 2024 country totals, split at 23.4° S using national census data (IBGE Brazil 2022, Stats SA 2022, Australian Bureau of Statistics): about 230 million people, under 3% of the world
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