Boston
232 km²
Sydney
12,368 km²
USA
Australia
Area Comparison
Boston is 53.3x smaller than Sydney
Population Comparison
Boston has 7.8x fewer people than Sydney
Sydney is significantly larger, covering 53.3 times the area of Boston. Sydney spans 12,368 km² (4,775 mi²) while Boston covers 232 km² (90 mi²) — a difference of 12,136 km². You could fit Boston inside Sydney approximately 53 times.
To put Boston's size in perspective, its area of 232 km² is roughly the same size as Amsterdam. Meanwhile, Sydney at 12,368 km² is about 2.0x the size of Shanghai.
Picture Boston another way: its area is large enough to fit about 32,000 American football fields, 110 times the area of Monaco, or 68 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.
Boston is the capital and most populous city of the U.S. state of Massachusetts. It serves as a cultural and financial center of New England, a region of the Northeastern United States. Boston has an area of 48.4 sq mi (125 km2) and a population of 675,647 as of the 2020 census, making it the third-most populous city in the Northeastern United States after New York City and Philadelphia.
Known as "Beantown", Boston covers 232 km² with a population of 0.7 million. The city was established in 1630. Boston is known for Fenway Park, Freedom Trail, Harvard University, among other attractions. The city's main transit system is the MBTA (The T).
Boston covers just 125 km2 yet serves as the cultural and financial heart of all New England
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. The city dates 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 1.1x larger than greater Boston at 11,700 km². The Sydney metro area is also more populous, with 5.3 million people compared to 4.9 million.
Boston has a population density of 2,931 people per km² — a moderately dense city. Sydney, with 429 people per km², is a low-density, sprawling urban area. Boston is dramatically more crowded, with 6.8x the population density.
This comparison spans continents — Boston in North America versus Sydney in Oceania. Despite the geographic distance, comparing their sizes reveals surprising insights about how cities grow worldwide.
Boston has a humid continental climate while Sydney experiences humid subtropical conditions. When it's noon in Sydney, it's midnight in Boston — a 15-hour time difference.
Size Ratio
Boston fits inside Sydney ~53 times
Density Gap
Boston is 6.8x more densely populated
Time Difference
15 hours apart
History
Boston is ~158 years older
Boston covers 232 km². Cities with a similar urban footprint include Osaka (225 km²), Kuala Lumpur (243 km²), Amsterdam (219 km²), Helsinki (214 km²), or Edinburgh (259 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 Boston to Sydney is 16,240 km (10,091 miles), with an estimated flight time of ~19h 36m.
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