Rio de Janeiro
1,221 km²
San Francisco
121 km²
1,221 km²
121 km²
Brazil
USA
Area Comparison
Rio de Janeiro is 10.1x larger than San Francisco
Population Comparison
Rio de Janeiro has 7.8x more people than San Francisco
Rio de Janeiro is significantly larger, covering 10.1 times the area of San Francisco. Rio de Janeiro spans 1,221 km² (471 mi²) while San Francisco covers 121 km² (47 mi²) — a difference of 1,100 km². You could fit San Francisco inside Rio de Janeiro approximately 10 times.
To put Rio de Janeiro's size in perspective, its area of 1,221 km² is about 1.3x smaller than London. Meanwhile, San Francisco at 121 km² is about 1.2x the size of Paris (city proper).
Rio de Janeiro's footprint is roughly about 171,000 American football fields, 21 times the area of Manhattan, or 12 times the area of Paris — pick whichever unit feels intuitive. San Francisco, by comparison, equals about 17,000 American football fields, 60 times the area of Monaco, or 35 times the area of Central Park.
Rio de Janeiro, also known simply as Rio, is the capital of the state of Rio de Janeiro. It is the second-most-populous city in Brazil after São Paulo and the sixth-most-populous city in the Americas.
Known as "Cidade Maravilhosa", Rio de Janeiro covers 1,221 km² with a population of 6.8 million. The city was established in 1565. Rio de Janeiro is known for Christ the Redeemer, Sugarloaf Mountain, Copacabana beach, among other attractions. The city's main transit system is the MetrôRio.
Rio de Janeiro is the second-most-populous city in Brazil after São Paulo and the sixth-most-populous in the Americas.
San Francisco, officially the City and County of San Francisco, is the fourth-most populous city in California and the 17th-most populous in the United States, with a population of 826,079 in 2025. Among U.S. cities with a population of 300,000 or more, San Francisco is ranked first by per capita income, second by population density, and sixth by aggregate income as of 2023.
Nicknamed "The City by the Bay", San Francisco has an area of 121 km² and is home to 0.9 million people. The city dates back to 1776. Visitors come for Golden Gate Bridge, Alcatraz Island, Cable cars, and much more. Getting around is easy with the BART & Muni.
San Francisco ranks first by per capita income among all US cities with 300,000+ residents as of 2023.
Looking beyond city limits, the San Francisco metropolitan area covers 6,984 km², which is 1.0x larger than greater Rio de Janeiro at 6,744 km². The Rio de Janeiro metro area is also more populous, with 13.5 million people compared to 4.7 million.
Rio de Janeiro has a population density of 5,528 people per km² — a densely populated city. San Francisco, with 7,190 people per km², is a densely populated city. Both cities have comparable density, though San Francisco is slightly more compact.
This comparison spans continents — Rio de Janeiro in South America versus San Francisco in North America. Despite the geographic distance, comparing their sizes reveals surprising insights about how cities grow worldwide.
Rio de Janeiro has a tropical savanna climate while San Francisco experiences Mediterranean conditions. Summers are notably different: Rio de Janeiro averages 27°C compared to 17°C in San Francisco. When it's noon in Rio de Janeiro, it's 7:00 AM in San Francisco — a 5-hour time difference.
Size Ratio
San Francisco fits inside Rio de Janeiro ~10 times
Density Gap
San Francisco is 1.3x more densely populated
Time Difference
5 hours apart
History
Rio de Janeiro is ~211 years older
Rio de Janeiro covers 1,221 km². Cities with a similar urban footprint include San Antonio (1,209 km²), Lagos (1,172 km²), Rome (1,285 km²), Los Angeles (1,302 km²), or Hong Kong (1,114 km²).
San Francisco covers 121 km². Cities with a similar urban footprint include Vancouver (115 km²), Paris (105 km²), Miami (143 km²), Barcelona (101 km²), or Lisbon (100 km²).
The straight-line distance from Rio de Janeiro to San Francisco is 10,662 km (6,625 miles), with an estimated flight time of ~13h 3m.
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