Perth
6,417 km²
Philadelphia
370 km²
Australia
United States
Area Comparison
Perth is 17.3x larger than Philadelphia
Population Comparison
Perth has 1.3x more people than Philadelphia
In terms of area, Perth is 17.3x the size of Philadelphia. Perth spans 6,417 km² (2,478 mi²) while Philadelphia covers 370 km² (143 mi²) — a difference of 6,047 km². You could fit Philadelphia inside Perth approximately 17 times.
To put Perth's size in perspective, its area of 6,417 km² is roughly the same size as Shanghai. Meanwhile, Philadelphia at 370 km² is about 1.6x smaller than Seoul.
In more relatable units, Perth's 6,417 km² is about 899,000 American football fields, 110 times the area of Manhattan, or 61 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.
Perth is the capital city of Western Australia. It is the fourth-most-populous city in Australia, with a population of over 2.3 million within Greater Perth as of 2023. The world's most isolated major city by certain criteria, Perth is part of the South West Land Division of Western Australia, with most of Perth's metropolitan area on the Swan Coastal Plain between the Indian Ocean and the Darling Scarp.
Known as "City of Light", Perth covers 6,417 km² with a population of 2.1 million. The city was established in 1829. Perth is known for Swan River, Kings Park, Cottesloe Beach, among other attractions.
Perth is considered the world's most isolated major city by certain criteria, sitting on Australia's west coast.
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.
Often called "Philly", Philadelphia has an area of 370 km² and is home to 1.6 million people. The city dates back to 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.
Perth has a population density of 333 people per km² — a low-density, sprawling urban area. Philadelphia, with 4,324 people per km², is a moderately dense city. Philadelphia is dramatically more crowded, with 13.0x the population density.
Size Ratio
Philadelphia fits inside Perth ~17 times
Density Gap
Philadelphia is 13.0x more densely populated
History
Philadelphia is ~147 years older
Perth covers 6,417 km². Cities with a similar urban footprint include Shanghai (6,341 km²), Guangzhou (7,434 km²), Istanbul (5,461 km²), Wuhan (8,569 km²), or Melbourne (9,993 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 Perth to Philadelphia is 18,685 km (11,610 miles), with an estimated flight time of ~22h 29m.
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