Hanoi
3,359 km²
San Antonio
1,209 km²
Vietnam
United States
Area Comparison
Hanoi is 2.8x larger than San Antonio
Population Comparison
Hanoi has 5.6x more people than San Antonio
Hanoi is significantly larger, covering 2.8 times the area of San Antonio. Hanoi spans 3,359 km² (1,297 mi²) while San Antonio covers 1,209 km² (467 mi²) — a difference of 2,150 km². You could fit San Antonio inside Hanoi approximately 2 times.
To put Hanoi's size in perspective, its area of 3,359 km² is about 1.2x smaller than Rhode Island. Meanwhile, San Antonio at 1,209 km² is about 1.3x smaller than London.
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. For San Antonio, that's about 169,000 American football fields, 20 times the area of Manhattan, or 11 times the area of Paris.
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 Antonio is a city in the U.S. state of Texas. It is the seventh-most populous city in the United States, the second-most populous city in Texas, and the second-most populous city in the Southern U.S., with a population of 1.43 million at the 2020 census. The Greater San Antonio metropolitan area, with an estimated 2.76 million residents, ranks as the third-largest metropolitan area in Texas and the 24th-largest in the nation. It is the county seat of Bexar County.
Nicknamed "Alamo City", San Antonio has an area of 1,209 km² and is home to 1.4 million people. Its history stretches back to 1718. Visitors come for The Alamo, San Antonio River Walk, Tower of the Americas, and much more.
San Antonio is the seventh-most populous city in the United States and second-most populous in Texas, with 1.43 million residents.
Hanoi has a population density of 2,397 people per km² — a moderately dense city. San Antonio, with 1,183 people per km², is a relatively spread-out city. Hanoi is noticeably denser, packing 2.0 times more people per square kilometer.
Size Ratio
San Antonio fits inside Hanoi ~2 times
Density Gap
Hanoi is 2.0x more densely populated
History
Hanoi is ~708 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 Antonio covers 1,209 km². Cities with a similar urban footprint include Rio de Janeiro (1,221 km²), Lagos (1,172 km²), Rome (1,285 km²), Los Angeles (1,302 km²), or Hong Kong (1,114 km²).
The straight-line distance from Hanoi to San Antonio is 13,829 km (8,593 miles), with an estimated flight time of ~16h 46m.
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