San Diego
964 km²
Shanghai
6,341 km²
United States
China
Area Comparison
San Diego is 6.6x smaller than Shanghai
Population Comparison
San Diego has 17.9x fewer people than Shanghai
Yes — Shanghai is 6.6x larger than San Diego by area. Shanghai spans 6,341 km² (2,448 mi²) while San Diego covers 964 km² (372 mi²) — a difference of 5,377 km². You could fit San Diego inside Shanghai approximately 6 times.
To put San Diego's size in perspective, its area of 964 km² is roughly the same size as Berlin. Meanwhile, Shanghai at 6,341 km² is about 1.5x the size of Los Angeles metro.
San Diego's footprint is roughly about 135,000 American football fields, 16 times the area of Manhattan, or 9 times the area of Paris — pick whichever unit feels intuitive. Shanghai works out to about 888,000 American football fields, 110 times the area of Manhattan, or 60 times the area of Paris.
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.
Known as "America's Finest City", San Diego covers 964 km² with a population of 1.4 million. The city was established in 1769. San Diego is known for San Diego Zoo, Balboa Park, Coronado Beach, among other attractions.
San Diego sits directly on the Mexico-United States border, making it California's southwesternmost major city.
Shanghai is a direct-administered municipality and the most populous urban area in China. It has a population of 29,558,908 in the urban area as of 2025. The city is located on the Chinese shoreline on the southern estuary of the Yangtze River, with the Huangpu River bisecting the city. Shanghai is a global center for finance, business and economics, research, science and technology, manufacturing, transportation, tourism, and culture. The Port of Shanghai is the world's busiest container port.
Also known as "Pearl of the Orient", Shanghai has an area of 6,341 km² and is home to 24.9 million people. The city dates back to 1291. Visitors come for The Bund, Oriental Pearl Tower, Shanghai Tower, and much more. Getting around is easy with the Shanghai Metro.
Shanghai's urban population reached 29.5 million in 2025, making it the most populous urban area in all of China.
San Diego has a population density of 1,442 people per km² — a relatively spread-out city. Shanghai, with 3,922 people per km², is a moderately dense city. Shanghai is noticeably denser, packing 2.7 times more people per square kilometer.
Size Ratio
San Diego fits inside Shanghai ~6 times
Density Gap
Shanghai is 2.7x more densely populated
History
Shanghai is ~478 years older
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).
Shanghai covers 6,341 km². Cities with a similar urban footprint include Perth (6,417 km²), Istanbul (5,461 km²), Guangzhou (7,434 km²), Wuhan (8,569 km²), or Dubai (4,114 km²).
The straight-line distance from San Diego to Shanghai is 10,609 km (6,592 miles), with an estimated flight time of ~12h 59m.
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