United States metropolitan area
In the United States, the Office of Management and Budget (OMB) has produced a formal definition of metropolitan areas, which are organized around county boundaries (except in New England, where cities and towns are more significant than counties as geographical and political units.) These are referred to as "Metropolitan Statistical Areas" (MSAs). If an MSA is large enough and can be subdivided into meaningful sub-metropolitan areas, then the MSA is considered a "Consolidated Metropolitan Statistical Area" (CMSA), with each subdivision called a "Primary Metropolitan Statistical Area" (PMSA). The largest MSAs in the United States are all CMSAs.
In 2003, further adjustments were made to the definition of metro areas, information about it is available on the core based statistical area entry.
The following is a list of the 25 most populated metropolitan areas in the United States, according to the 2000 Census:
| Rank | Metropolitan Area | States/Territories | Type | Population | Other names (not necessarily equivalent to the Census definition of the metropolitan area) |
|---|---|---|---|---|---|
| 1 | New York--Northern New Jersey (Jersey City, Trenton, Newark)--Long Island--Bridgeport--New Haven | NY--NJ--CT--PA | CMSA | 21,199,865 | Tri-state Area, New York area, Greater New York |
| 2 | Los Angeles--Riverside--Orange County | CA | CMSA | 16,373,645 | The Southland, Southern California (The latter also refers to the entire southern portion of the state) |
| 3 | Chicago--Joliet--Naperville--Gary--Kenosha | IL--IN--WI | CMSA | 9,157,540 | Chicagoland, Greater Chicago, Chicagoland and Northwest Indiana (the latter refers to the eastern part extended until South Bend, Indiana) |
| 4 | Washington--Baltimore | DC--MD--VA--WV | CMSA | 7,608,070 | Baltimore-Washington Metropolitan Area |
| 5 | San Francisco--Oakland--San Jose | CA | CMSA | 7,039,362 | The Bay Area |
| 6 | Philadelphia--Wilmington--Atlantic City | PA--NJ--DE--MD | CMSA | 6,188,463 | The Delaware Valley |
| 7 | Boston--Worcester--Lawrence | MA--NH--ME--CT | CMSA | 5,819,100 | Greater Boston |
| 8 | Detroit--Ann Arbor--Flint* | MI | CMSA | 5,456,428 | Metro Detroit |
| 9 | Dallas--Fort Worth--Arlington | TX | CMSA | 5,221,801 | The Metroplex, DFW |
| 10 | Houston--Galveston--Brazoria--Baytown--Sugar Land | TX | CMSA | 4,669,571 | Houston Metropolitan Area |
| 11 | Atlanta | GA | MSA | 4,112,198 | Atlanta Metropolitan Area |
| 12 | Miami--Ft. Lauderdale | FL | CMSA | 3,876,380 | |
| 13 | Seattle--Tacoma--Bremerton | WA | CMSA | 3,554,760 | Greater Puget Sound |
| 14 | Phoenix--Mesa | AZ | MSA | 3,251,876 | The Valley of the Sun |
| 15 | Minneapolis--St. Paul | MN, WI | MSA | 2,968,806 | The Twin Cities |
| 16 | Cleveland--Akron | OH | CMSA | 2,945,831 | Greater Cleveland, Northeast Ohio |
| 17 | San Diego | CA | MSA | 2,813,833 |
|
| 18 | St. Louis | MO, IL | MSA | 2,603,607 | Greater St. Louis
|
| 19 | Denver--Boulder--Greeley | CO | CMSA | 2,581,506 |
|
| 20 | San Juan--Caguas--Arecibo | PR | CMSA | 2,450,292 |
|
| 21 | Tampa--St. Petersburg--Clearwater | FL | MSA | 2,395,997 |
|
| 22 | Pittsburgh--New Castle | PA | MSA | 2,512,302 |
|
| 23 | Portland--Salem--Vancouver | OR, WA | CMSA | 1,979,202 |
|
| 24 | Cincinnati--Hamilton | OH, KY, IN | CMSA | 1,979,202 | Greater Cincinnati/Northern Kentucky |
*This is the metropolitan area of Detroit within US borders. A larger metropolitan area containing the Windsor, Ontario area is used internationally.