Barcelona
101 km²
San Francisco
121 km²
Spain
USA
Area Comparison
Barcelona is 1.2x smaller than San Francisco
Population Comparison
Barcelona has 1.9x more people than San Francisco
In terms of area, San Francisco is 1.2x the size of Barcelona. San Francisco spans 121 km² (47 mi²) while Barcelona covers 101 km² (39 mi²) — a difference of 20 km².
To put Barcelona's size in perspective, its area of 101 km² is roughly the same size as Paris (city proper). Meanwhile, San Francisco at 121 km² is about 1.2x the size of Paris (city proper).
Picture Barcelona another way: its area is large enough to fit about 14,000 American football fields, 50 times the area of Monaco, or 30 times the area of Central Park. 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.
Barcelona is a city on the northeastern coast of Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second-most populous municipality of Spain. With a population of 1.7 million within city limits, its urban area extends to numerous neighbouring municipalities within the province of Barcelona and is home to around 5.7 million people, making it the fifth most populous urban area of the European Union after Paris, the Ruhr area, Madrid and Milan.
Known as "Ciutat Comtal", Barcelona covers 101 km² with a population of 1.7 million. The city was founded around 230 BC. Barcelona is known for Sagrada Familia, Park Güell, La Rambla, among other attractions. The city's main transit system is the Barcelona Metro (TMB).
Barcelona is the second-most populous municipality in Spain and the capital of the autonomous community of Catalonia.
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. 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 8.7x larger than greater Barcelona at 803 km². The Barcelona metro area is also more populous, with 5.6 million people compared to 4.7 million.
Barcelona has a population density of 16,436 people per km² — an extremely dense urban environment. San Francisco, with 7,190 people per km², is a densely populated city. Barcelona is noticeably denser, packing 2.3 times more people per square kilometer.
This comparison spans continents — Barcelona in Europe versus San Francisco in North America. Despite the geographic distance, comparing their sizes reveals surprising insights about how cities grow worldwide.
Both cities share a Mediterranean climate, though local geography creates distinct microclimates in each. When it's noon in Barcelona, it's 3:00 AM in San Francisco — a 9-hour time difference.
Density Gap
Barcelona is 2.3x more densely populated
Time Difference
9 hours apart
History
Barcelona is ~2,006 years older
Barcelona covers 101 km². Cities with a similar urban footprint include Lisbon (100 km²), Paris (105 km²), Copenhagen (91 km²), Vancouver (115 km²), or Zurich (88 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 Barcelona to San Francisco is 9,572 km (5,948 miles), with an estimated flight time of ~11h 46m.
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