Hanoi
3,359 km²
Sydney
12,368 km²
Vietnam
Australia
Area Comparison
Hanoi is 3.7x smaller than Sydney
Population Comparison
Hanoi has 1.5x more people than Sydney
Yes — Sydney is 3.7x larger than Hanoi by area. Sydney spans 12,368 km² (4,775 mi²) while Hanoi covers 3,359 km² (1,297 mi²) — a difference of 9,009 km². You could fit Hanoi inside Sydney approximately 3 times.
To put Hanoi's size in perspective, its area of 3,359 km² is about 1.2x smaller than Rhode Island. Meanwhile, Sydney at 12,368 km² is about 2.0x the size of Shanghai.
Picture Hanoi another way: its area is large enough to fit about 470,000 American football fields, 57 times the area of Manhattan, or 32 times the area of Paris. Sydney works out to about 1,700,000 American football fields, 120 times the area of Paris, or 100 times the area of San Francisco.
Hanoi is the capital and second-most populous municipality of Vietnam. It encompasses an area of 3,358.6 km2 (1,296.8 mi2), and as of 2025 has a population of 8,807,523. Hanoi had the second-highest gross regional domestic product of all Vietnamese provinces and municipalities at US$48 billion in 2023, behind Ho Chi Minh City. It hosts 78 foreign embassies, the headquarters of the Vietnam People's Army (VPA), its Vietnam National University system, and other governmental organizations.
Known as "City Between Rivers", Hanoi covers 3,359 km² with a population of 8.1 million. The city was established in 1010. Hanoi is known for Hoan Kiem Lake, Old Quarter, Temple of Literature, among other attractions. The city's main transit system is the Hanoi Metro.
Hanoi encompasses 3,358.6 square kilometers and had a population of nearly 8.8 million as of 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.
Nicknamed "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 3.7x larger than greater Hanoi at 3,359 km². The Hanoi metro area is also more populous, with 8.1 million people compared to 5.3 million.
Hanoi has a population density of 2,397 people per km² — a moderately dense city. Sydney, with 429 people per km², is a low-density, sprawling urban area. Hanoi is dramatically more crowded, with 5.6x the population density.
This comparison spans continents — Hanoi in Asia versus Sydney in Oceania. Despite the geographic distance, comparing their sizes reveals surprising insights about how cities grow worldwide.
Both cities share a humid subtropical climate, though local geography creates distinct microclimates in each. When it's noon in Sydney, it's 9:00 AM in Hanoi — a 3-hour time difference.
Size Ratio
Hanoi fits inside Sydney ~3 times
Density Gap
Hanoi is 5.6x more densely populated
Time Difference
3 hours apart
History
Hanoi is ~778 years older
Hanoi covers 3,359 km². Cities with a similar urban footprint include Karachi (3,527 km²), Cairo (3,085 km²), Dubai (4,114 km²), Lima (2,672 km²), or Moscow (2,511 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 Hanoi to Sydney is 7,767 km (4,826 miles), with an estimated flight time of ~9h 38m.
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