Philadelphia
370 km²
San Francisco
121 km²
United States
USA
Area Comparison
Philadelphia is 3.1x larger than San Francisco
Population Comparison
Philadelphia has 1.8x more people than San Francisco
In terms of area, Philadelphia is 3.1x the size of San Francisco. Philadelphia spans 370 km² (143 mi²) while San Francisco covers 121 km² (47 mi²) — a difference of 249 km². You could fit San Francisco inside Philadelphia approximately 3 times.
To put Philadelphia's size in perspective, its area of 370 km² is about 1.6x smaller than Seoul. Meanwhile, San Francisco at 121 km² is about 1.2x the size of Paris (city proper).
Philadelphia's footprint is roughly about 52,000 American football fields, 180 times the area of Monaco, or 110 times the area of Central Park — pick whichever unit feels intuitive. San Francisco works out to about 17,000 American football fields, 60 times the area of Monaco, or 35 times the area of Central Park.
Philadelphia, colloquially referred to as Philly, is the most populous city in the U.S. state of Pennsylvania, and the sixth-most populous city in the United States, with a Census-estimated population of 1,574,281 in July 2025. The Philadelphia metropolitan area has 6.33 million residents and is the nation's ninth-largest metropolitan area. Philadelphia is known for its culture, cuisine, and history, maintaining contemporary influence in business and technology, sports, and music.
Known as "Philly", Philadelphia covers 370 km² with a population of 1.6 million. The city was established in 1682. Philadelphia is known for Liberty Bell, Independence Hall, Philly Cheesesteak, among other attractions.
Philadelphia is the sixth-most populous US city, with an estimated 1,574,281 residents as of July 2025.
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. 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.
Philadelphia has a population density of 4,324 people per km² — a moderately dense city. San Francisco, with 7,190 people per km², is a densely populated city. San Francisco is noticeably denser, packing 1.7 times more people per square kilometer.
Size Ratio
San Francisco fits inside Philadelphia ~3 times
Density Gap
San Francisco is 1.7x more densely populated
Philadelphia covers 370 km². Cities with a similar urban footprint include Seattle (369 km²), Dhaka (368 km²), Portland (376 km²), Atlanta (348 km²), or Denver (401 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 Philadelphia to San Francisco is 4,051 km (2,517 miles), with an estimated flight time of ~5h 16m.
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