London
1,572 km²
Philadelphia
370 km²
UK
United States
Area Comparison
London is 4.2x larger than Philadelphia
Population Comparison
London has 5.6x more people than Philadelphia
In terms of area, London is 4.2x the size of Philadelphia. London spans 1,572 km² (607 mi²) while Philadelphia covers 370 km² (143 mi²) — a difference of 1,202 km². You could fit Philadelphia inside London approximately 4 times.
To put London's size in perspective, its area of 1,572 km² is about 1.4x smaller than Tokyo (city proper). Meanwhile, Philadelphia at 370 km² is about 1.6x smaller than Seoul.
Picture London another way: its area is large enough to fit about 220,000 American football fields, 27 times the area of Manhattan, or 15 times the area of Paris. Philadelphia works out to about 52,000 American football fields, 180 times the area of Monaco, or 110 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.
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.
Nicknamed "Philly", Philadelphia has an area of 370 km² and is home to 1.6 million people. It was established in 1682. Visitors come for Liberty Bell, Independence Hall, Philly Cheesesteak, and much more.
Philadelphia is the sixth-most populous US city, with an estimated 1,574,281 residents as of July 2025.
London has a population density of 5,712 people per km² — a densely populated city. Philadelphia, with 4,324 people per km², is a moderately dense city. Both cities have comparable density, though London is slightly more compact.
Size Ratio
Philadelphia fits inside London ~4 times
Density Gap
London is 1.3x more densely populated
History
London is ~1,639 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).
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).
The straight-line distance from London to Philadelphia is 5,700 km (3,542 miles), with an estimated flight time of ~7h 12m.
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