Anchorage is located in South Central Alaska. It lies slightly farther north than Oslo, Stockholm, Helsinki and St. Petersburg. It is northeast of the Alaska Peninsula, Kodiak Island, and Cook Inlet, due north of the Kenai Peninsula, northwest of Prince William Sound and Alaska Panhandle, and nearly due south of Mount McKinley/Denali.
The city is on a strip of coastal lowland and extends up the lower alpine slopes of the Chugach Mountains. To the south is Turnagain Arm, a fjord that has some of the world's highest tides. Knik Arm, another tidal inlet, lies to the west and north. The Chugach Mountains on the east form a boundary to development, but not to the city limits, which encompass part of the wild alpine territory of Chugach State Park.
The city's seacoast consists mostly of treacherous mudflats. Newcomers and tourists are warned not to walk in this area because of extreme tidal changes and sticky mud.
To the north is Matanuska-Susitna Borough (Mat-Su Valley), which is included with the MOA as a metropolitan area by the US Census Bureau. Although the Mat-Su is a "bedroom community" for Anchorage, the towns, exurbs, farms, and homesteads there have varied local cultures quite distinct from that of Anchorage proper. Between metropolitan Anchorage and the valley, the communities of Eagle River and Chugiak, though part of the MOA, also have distinct identities.
According to the United States Census Bureau, the municipality has a total area of 1,961.1 square miles (5,079.2 km²), of which 1,697.2 square miles (4,395.8 km²) is land and 263.9 square miles (683.4 km²) is water. The total area is 13.46% water. The area of Anchorage is thus larger than that of the state of Rhode Island.