Buenos Aires
203 km²
Hanoi
3,359 km²
Argentina
Vietnam
Area Comparison
Buenos Aires is 16.5x smaller than Hanoi
Population Comparison
Buenos Aires has 2.6x fewer people than Hanoi
Hanoi is significantly larger, covering 16.5 times the area of Buenos Aires. Hanoi spans 3,359 km² (1,297 mi²) while Buenos Aires covers 203 km² (78 mi²) — a difference of 3,156 km². You could fit Buenos Aires inside Hanoi approximately 16 times.
To put Buenos Aires's size in perspective, its area of 203 km² is roughly the same size as Amsterdam. Meanwhile, Hanoi at 3,359 km² is about 1.2x smaller than Rhode Island.
Picture Buenos Aires another way: its area is large enough to fit about 28,000 American football fields, 100 times the area of Monaco, or 60 times the area of Central Park. Hanoi, by comparison, equals about 470,000 American football fields, 57 times the area of Manhattan, or 32 times the area of Paris.
Buenos Aires, officially the Autonomous City of Buenos Aires, is the capital and largest city of Argentina. It is located on the southwest of the Río de la Plata. Buenos Aires is classified as an Alpha− global city, according to the GaWC 2024 ranking. The city proper has a population of 3.1 million and its urban area has a population of 16.7 million, making it the 21st most populous metropolitan area in the world.
Known as "Paris of South America", Buenos Aires covers 203 km² with a population of 3.1 million. The city was established in 1536. Buenos Aires is known for La Boca's Caminito, Recoleta Cemetery, Teatro Colón, among other attractions. The city's main transit system is the Buenos Aires Subte.
Buenos Aires is classified as an Alpha− global city according to the GaWC 2024 ranking.
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.
Also known as "City Between Rivers", Hanoi has an area of 3,359 km² and is home to 8.1 million people. Its history stretches back to 1010. Visitors come for Hoan Kiem Lake, Old Quarter, Temple of Literature, and much more. Getting around is easy with the Hanoi Metro.
Hanoi encompasses 3,358.6 square kilometers and had a population of nearly 8.8 million as of 2025.
Looking beyond city limits, the Buenos Aires metropolitan area covers 4,758 km², which is 1.4x larger than greater Hanoi at 3,359 km². The Buenos Aires metro area is also more populous, with 15.2 million people compared to 8.1 million.
Buenos Aires has a population density of 15,074 people per km² — an extremely dense urban environment. Hanoi, with 2,397 people per km², is a moderately dense city. Buenos Aires is dramatically more crowded, with 6.3x the population density.
This comparison spans continents — Buenos Aires in South America versus Hanoi in Asia. 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 Hanoi, it's 2:00 AM in Buenos Aires — a 10-hour time difference.
Size Ratio
Buenos Aires fits inside Hanoi ~16 times
Density Gap
Buenos Aires is 6.3x more densely populated
Time Difference
10 hours apart
History
Hanoi is ~526 years older
Buenos Aires covers 203 km². Cities with a similar urban footprint include Helsinki (214 km²), Amsterdam (219 km²), Stockholm (188 km²), Osaka (225 km²), or Boston (232 km²).
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).
The straight-line distance from Buenos Aires to Hanoi is 17,855 km (11,095 miles), with an estimated flight time of ~21h 30m.
Want to explore more? Compare city sizes for any two cities worldwide, or share your location live with friends.