Philadelphia
370 km²
San Diego
964 km²
United States
United States
Area Comparison
Philadelphia is 2.6x smaller than San Diego
Population Comparison
Philadelphia has 1.2x more people than San Diego
Yes — San Diego is 2.6x larger than Philadelphia by area. San Diego spans 964 km² (372 mi²) while Philadelphia covers 370 km² (143 mi²) — a difference of 594 km². You could fit Philadelphia inside San Diego approximately 2 times.
To put Philadelphia's size in perspective, its area of 370 km² is about 1.6x smaller than Seoul. Meanwhile, San Diego at 964 km² is roughly the same size as Berlin.
Picture Philadelphia another way: its area is large enough to fit about 52,000 American football fields, 180 times the area of Monaco, or 110 times the area of Central Park. For San Diego, that's about 135,000 American football fields, 16 times the area of Manhattan, or 9 times the area of Paris.
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 Diego is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. It is the eighth-most populous city in the U.S. and second-most populous city in California with a population of over 1.4 million, while the San Diego metropolitan area with over 3.3 million residents is the 18th-largest metropolitan area in the country. San Diego is the county seat of San Diego County.
Also known as "America's Finest City", San Diego has an area of 964 km² and is home to 1.4 million people. Its history stretches back to 1769. Visitors come for San Diego Zoo, Balboa Park, Coronado Beach, and much more.
San Diego sits directly on the Mexico-United States border, making it California's southwesternmost major city.
Philadelphia has a population density of 4,324 people per km² — a moderately dense city. San Diego, with 1,442 people per km², is a relatively spread-out city. Philadelphia is noticeably denser, packing 3.0 times more people per square kilometer.
Size Ratio
Philadelphia fits inside San Diego ~2 times
Density Gap
Philadelphia is 3.0x 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 Diego covers 964 km². Cities with a similar urban footprint include Abu Dhabi (972 km²), Dallas (997 km²), Berlin (892 km²), Santiago (838 km²), or Hong Kong (1,114 km²).
The straight-line distance from Philadelphia to San Diego is 3,811 km (2,368 miles), with an estimated flight time of ~4h 59m.
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