San Francisco
121 km²
Sydney
12,368 km²
USA
Australia
Area Comparison
San Francisco is 102.2x smaller than Sydney
Population Comparison
San Francisco has 6.1x fewer people than Sydney
In terms of area, Sydney is 102.2x the size of San Francisco. Sydney spans 12,368 km² (4,775 mi²) while San Francisco covers 121 km² (47 mi²) — a difference of 12,247 km². You could fit San Francisco inside Sydney approximately 102 times.
To put San Francisco's size in perspective, its area of 121 km² is about 1.2x the size of Paris (city proper). Meanwhile, Sydney at 12,368 km² is about 2.0x the size of Shanghai.
Picture San Francisco another way: its area is large enough to fit about 17,000 American football fields, 60 times the area of Monaco, or 35 times the area of Central Park. For Sydney, that's about 1,700,000 American football fields, 120 times the area of Paris, or 100 times the area of San Francisco.
San Francisco, officially the City and County of San Francisco, is the fourth-most populous city in California and the 17th-most populous in the United States, with a population of 826,079 in 2025. Among U.S. cities with a population of 300,000 or more, San Francisco is ranked first by per capita income, second by population density, and sixth by aggregate income as of 2023.
Known as "The City by the Bay", San Francisco covers 121 km² with a population of 0.9 million. The city was established in 1776. San Francisco is known for Golden Gate Bridge, Alcatraz Island, Cable cars, among other attractions. The city's main transit system is the BART & Muni.
San Francisco ranks first by per capita income among all US cities with 300,000+ residents as of 2023.
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.
Looking beyond city limits, the Sydney metropolitan area covers 12,368 km², which is 1.8x larger than greater San Francisco at 6,984 km². The Sydney metro area is also more populous, with 5.3 million people compared to 4.7 million.
San Francisco has a population density of 7,190 people per km² — a densely populated city. Sydney, with 429 people per km², is a low-density, sprawling urban area. San Francisco is dramatically more crowded, with 16.8x the population density.
This comparison spans continents — San Francisco in North America versus Sydney in Oceania. Despite the geographic distance, comparing their sizes reveals surprising insights about how cities grow worldwide.
San Francisco has a Mediterranean climate while Sydney experiences humid subtropical conditions. When it's noon in Sydney, it's midnight in San Francisco — a 18-hour time difference.
Size Ratio
San Francisco fits inside Sydney ~102 times
Density Gap
San Francisco is 16.8x more densely populated
Time Difference
18 hours apart
San Francisco covers 121 km². Cities with a similar urban footprint include Vancouver (115 km²), Paris (105 km²), Miami (143 km²), Barcelona (101 km²), or Lisbon (100 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 San Francisco to Sydney is 11,948 km (7,424 miles), with an estimated flight time of ~14h 33m.
Want to explore more? Compare city sizes for any two cities worldwide, or share your location live with friends.