What is the size of the US

Checked on January 11, 2026
Disclaimer: Factually can make mistakes. Please verify important information or breaking news. Learn more.

This fact-check may be outdated. Consider refreshing it to get the most current information.

Executive summary

The United States covers roughly 9.15 million square kilometres (about 3.53 million square miles) of land, with a larger total surface area when inland water is included—commonly reported near 3.79 to 3.80 million square miles—placing the country among the world’s three or four largest depending on counting methods [1] [2] [3]. Beyond its landmass, the U.S. asserts one of the world’s largest exclusive economic zones in the ocean, on the order of 11–11.7 million km2 (about 4.38–4.5 million square miles), a figure that is reported with modest variation across sources [4] [5].

1. Land area: the commonly cited baseline

The standard, internationally reported land-area figure for the United States is about 9,147,420 km2 (3,531,839 sq mi), a World Bank–compiled number widely used in statistical datasets and reflected in contemporary summaries of U.S. land extent [1] [2]. That land-only measure excludes inland water bodies and is the figure most often used when ranking countries by landmass; it aligns with other public data sources that list the contiguous forty-eight states plus Alaska and Hawaii within the 50-state federation [6] [2].

2. Total surface area (land + inland water): a larger footprint

When inland water is included the U.S. total surface area grows: reputable summaries give total sizes near 3.79–3.80 million square miles (roughly 9.84 million km2), which is why encyclopedias and geography references sometimes state that the United States is the world’s third or fourth largest country depending on which total-area definition and which territorial claims are applied [2] [3]. These distinctions matter for global ranking because small differences in how coastal waters and disputed territories are counted can flip the U.S. relative position with China and, in some lists, with other large states [4] [3].

3. Marine area: the massive Exclusive Economic Zone

Beyond continental measures, the U.S. controls an exceptionally large maritime economic space: sources report the U.S. Exclusive Economic Zone (EEZ) at roughly 11.35 million km2 (about 4.383 million sq mi) in one account and roughly 11.7 million km2 (about 4.5 million sq mi) in another, reflecting minor methodological differences in how distant territories and maritime features are counted [4] [5]. That marine area substantially increases the geographic footprint of U.S. jurisdiction on ocean resources and is why some overviews highlight the nation’s vast oceanic reach separate from its terrestrial ranking [4] [5].

4. Other ways to express size: acres and land use

Federal agricultural and land-use reporting frames the national extent in acres: the U.S. land base is described as nearly 2.26 billion acres in USDA Economic Research Service summaries, a unit that matters for policy on farming, grazing, conservation and public lands [7]. Those land-use breakdowns illustrate that the raw geometric size is only part of the story: ownership patterns, public-land percentages (noted elsewhere as roughly 28% federally owned), and how acreage is allocated between cropland, forest and rangeland shape economic and conservation realities on that surface [7] [5].

5. Why numbers vary and what to watch for in reporting

Discrepancies across reputable sources stem from definitional choices—land only versus land-plus-inland-water, inclusion of territories and how maritime zones are tallied—and from geopolitical ambiguities that affect global rank comparisons (for example, contested claims that affect China’s reported area) [4] [3]. Reporting must therefore state which measure it uses: “land area” (~9.15 million km2 / 3.53 million sq mi) is the baseline; “total surface area” (near 3.79–3.80 million sq mi / ~9.84 million km2) is larger; and the EEZ (about 11–11.7 million km2) is an additional oceanic domain that vastly expands U.S. jurisdiction at sea [1] [2] [4] [5]. Where sources disagree, the available reporting documents the range rather than a single absolute number [4] [5].

Want to dive deeper?
How does the United States' land area compare to China and Russia using different measurement methods?
What portion of U.S. land is federally owned or protected, and how has that share changed over time?
How is the U.S. Exclusive Economic Zone defined and which territories contribute most to its size?