Philadelphia
370 km²
Sydney
12,368 km²
United States
Australia
Area Comparison
Philadelphia is 33.4x smaller than Sydney
Population Comparison
Philadelphia has 3.3x fewer people than Sydney
Yes — Sydney is 33.4x larger than Philadelphia by area. Sydney spans 12,368 km² (4,775 mi²) while Philadelphia covers 370 km² (143 mi²) — a difference of 11,998 km². You could fit Philadelphia inside Sydney approximately 33 times.
To put Philadelphia's size in perspective, its area of 370 km² is about 1.6x smaller than Seoul. Meanwhile, Sydney at 12,368 km² is about 2.0x the size of Shanghai.
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. Sydney, by comparison, equals about 1,700,000 American football fields, 120 times the area of Paris, or 100 times the area of San Francisco.
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.
Sydney is the capital city of the state of New South Wales, and is the most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about 80 kilometres (50 mi) from the Pacific Ocean in the east to the Blue Mountains in the west, and about 80 kilometres (50 mi) from Ku-ring-gai Chase National Park and the Hawkesbury River in the north and north-west, to the Royal National Park and Macarthur in the south and south-west.
Also known as "Sydneysiders", Sydney has an area of 12,368 km² and is home to 5.3 million people. Its history stretches back to 1788. Visitors come for Sydney Opera House, Sydney Harbour Bridge, Bondi Beach, and much more. Getting around is easy with the Sydney Trains.
Sydney stretches roughly 80 km from the Pacific Ocean in the east to the Blue Mountains in the west.
Philadelphia has a population density of 4,324 people per km² — a moderately dense city. Sydney, with 429 people per km², is a low-density, sprawling urban area. Philadelphia is dramatically more crowded, with 10.1x the population density.
Size Ratio
Philadelphia fits inside Sydney ~33 times
Density Gap
Philadelphia is 10.1x more densely populated
History
Philadelphia is ~106 years older
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).
Sydney covers 12,368 km². Cities with a similar urban footprint include Chengdu (14,378 km²), Xi'an (10,097 km²), Melbourne (9,993 km²), Brisbane (15,826 km²), or Beijing (16,411 km²).
The straight-line distance from Philadelphia to Sydney is 15,884 km (9,870 miles), with an estimated flight time of ~19h 11m.
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