London
1,572 km²
San Francisco
121 km²
UK
USA
Area Comparison
London is 13.0x larger than San Francisco
Population Comparison
London has 10.3x more people than San Francisco
London is significantly larger, covering 13.0 times the area of San Francisco. London spans 1,572 km² (607 mi²) while San Francisco covers 121 km² (47 mi²) — a difference of 1,451 km². You could fit San Francisco inside London approximately 12 times.
To put London's size in perspective, its area of 1,572 km² is about 1.4x smaller than Tokyo (city proper). Meanwhile, San Francisco at 121 km² is about 1.2x the size of Paris (city proper).
London's footprint is roughly about 220,000 American football fields, 27 times the area of Manhattan, or 15 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.
London is the capital and largest city of England and the United Kingdom, with a population of 9.1 million people in 2024. Its wider metropolitan area is the largest in Western Europe, with a population of 15.1 million. London stands on the River Thames in southeast England, at the head of a 50-mile (80 km) tidal estuary down to the North Sea, and has been a major settlement for nearly 2,000 years.
Known as "The Big Smoke", London covers 1,572 km² with a population of 9.0 million. The city was established in 43. London is known for Big Ben, Tower Bridge, Buckingham Palace, among other attractions. The city's main transit system is the London Underground.
London has been a major settlement for nearly 2,000 years, tracing its roots back to Roman times around 47 AD.
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.
Also known as "The City by the Bay", San Francisco has an area of 121 km² and is home to 0.9 million people. Its history stretches 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 London metropolitan area covers 8,382 km², which is 1.2x larger than greater San Francisco at 6,984 km². The London metro area is also more populous, with 14.3 million people compared to 4.7 million.
London has a population density of 5,712 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 — London in Europe versus San Francisco in North America. Despite the geographic distance, comparing their sizes reveals surprising insights about how cities grow worldwide.
London has a oceanic climate while San Francisco experiences Mediterranean conditions. When it's noon in London, it's 4:00 AM in San Francisco — a 8-hour time difference.
Size Ratio
San Francisco fits inside London ~12 times
Time Difference
8 hours apart
History
London is ~1,733 years older
London covers 1,572 km². Cities with a similar urban footprint include Bangkok (1,569 km²), Bogotá (1,578 km²), São Paulo (1,521 km²), Johannesburg (1,644 km²), or Mexico City (1,485 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 London to San Francisco is 8,616 km (5,354 miles), with an estimated flight time of ~10h 38m.
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