Area comparison map:

about six times the size of Georgia; slightly more than twice the size of CaliforniaLand boundaries:
total: 4,477 km
[see also: Land boundaries - total country ranks ]
border countries (4): Benin 809 km, Cameroon 1975 km, Chad 85 km, Niger 1608 km

Coastline:
853 km
[see also: Coastline country ranks ]

Maritime claims:
territorial sea: 12 nm
[see also: Maritime claims - territorial sea country ranks ]
exclusive economic zone: 200 nm
[see also: Maritime claims - exclusive economic zone country ranks ]
continental shelf: 200-m depth or to the depth of exploitation
[see also: Maritime claims - continental shelf country ranks ]

Climate:
varies; equatorial in south, tropical in center, arid in north
More Climate Details

Terrain:
southern lowlands merge into central hills and plateaus; mountains in southeast, plains in north

Elevation:
mean elevation: 380 m
[see also: Elevation - mean elevation country ranks ]
lowest point: Atlantic Ocean 0 m
highest point: Chappal Waddi 2,419 m

Natural resources:
natural gas, petroleum, tin, iron ore, coal, limestone, niobium, lead, zinc, arable land

Land use:
agricultural land: 78% (2011 est.)
[see also: Land use - agricultural land country ranks ]
arable land: 37.3% (2011 est.)
[see also: Land use - arable land country ranks ]
permanent crops: 7.4% (2011 est.)
[see also: Land use - permanent crops country ranks ]
permanent pasture: 33.3% (2011 est.)
[see also: Land use - permanent pasture country ranks ]
forest: 9.5% (2011 est.)
[see also: Land use - forest country ranks ]
other: 12.5% (2011 est.)
[see also: Land use country ranks ]

Irrigated land:
2,930 sq km (2012)
[see also: Irrigated land country ranks ]

Population distribution:
largest population of any African nation; significant population clusters are scattered throughout the country, with the highest density areas being in the south and southwest

Natural hazards:
periodic droughts; flooding

Environment - current issues:
serious overpopulation and rapid urbanization have led to numerous environmental problems; urban air and water pollution; rapid deforestation; soil degradation; loss of arable land; oil pollution - water, air, and soil have suffered serious damage from oil spills

Environment - international agreements:
party to: Biodiversity, Climate Change, Climate Change-Kyoto Protocol, Desertification, Endangered Species, Hazardous Wastes, Law of the Sea, Marine Dumping, Marine Life Conservation, Ozone Layer Protection, Ship Pollution, Wetlands
signed, but not ratified: none of the selected agreements

Geography - note:
the Niger River enters the country in the northwest and flows southward through tropical rain forests and swamps to its delta in the Gulf of Guinea