Hanoi
3,359 km²
San Francisco
121 km²
Vietnam
USA
Area Comparison
Hanoi is 27.8x larger than San Francisco
Population Comparison
Hanoi has 9.3x more people than San Francisco
Yes — Hanoi is 27.8x larger than San Francisco by area. Hanoi spans 3,359 km² (1,297 mi²) while San Francisco covers 121 km² (47 mi²) — a difference of 3,238 km². You could fit San Francisco inside Hanoi approximately 27 times.
To put Hanoi's size in perspective, its area of 3,359 km² is about 1.2x smaller than Rhode Island. Meanwhile, San Francisco at 121 km² is about 1.2x the size of Paris (city proper).
In more relatable units, Hanoi's 3,359 km² is about 470,000 American football fields, 57 times the area of Manhattan, or 32 times the area of Paris. San Francisco works out to about 17,000 American football fields, 60 times the area of Monaco, or 35 times the area of Central Park.
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.
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.
Nicknamed "The City by the Bay", San Francisco has an area of 121 km² and is home to 0.9 million people. Its history stretches back to 1776. Visitors come for Golden Gate Bridge, Alcatraz Island, Cable cars, and much more. Getting around is easy with the BART & Muni.
San Francisco ranks first by per capita income among all US cities with 300,000+ residents as of 2023.
Looking beyond city limits, the San Francisco metropolitan area covers 6,984 km², which is 2.1x larger than greater Hanoi at 3,359 km². The Hanoi metro area is also more populous, with 8.1 million people compared to 4.7 million.
Hanoi has a population density of 2,397 people per km² — a moderately dense city. San Francisco, with 7,190 people per km², is a densely populated city. San Francisco is noticeably denser, packing 3.0 times more people per square kilometer.
This comparison spans continents — Hanoi in Asia versus San Francisco in North America. Despite the geographic distance, comparing their sizes reveals surprising insights about how cities grow worldwide.
Hanoi has a humid subtropical climate while San Francisco experiences Mediterranean conditions. Summers are notably different: Hanoi averages 30°C compared to 17°C in San Francisco. When it's noon in Hanoi, it's midnight in San Francisco — a 15-hour time difference.
Size Ratio
San Francisco fits inside Hanoi ~27 times
Density Gap
San Francisco is 3.0x more densely populated
Time Difference
15 hours apart
History
Hanoi is ~766 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).
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).
The straight-line distance from Hanoi to San Francisco is 11,759 km (7,307 miles), with an estimated flight time of ~14h 20m.
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