Bihar is the state in India, 3rd most populous (103,804,637 estimates of 2011) and the 12th extensive state by area (98,940 km2) with a density of 1,102 inhabitants per km2. There are more than 25 cities with over 100,000 population, the state is highly populated and densely inhabited. Patna is the capital and largest city of Bihar state covered area of 135 km2 with a population of 2,049,156, a density of 15,157 inhabitants per km2. 25 cities listed below with Population, Area, Density and districts of the cities, largest cities in Bihar ranked by the total population of the cities.
| Rank | City Name | Population | Area (km²) | Density ( inhabitants/km²) | District |
|---|---|---|---|---|---|
| 1 | Patna | 2,049,156 | 135 | 15,157 | Patna |
| 2 | Gaya | 475,987 | 51 | 9,244 | Gaya |
| 3 | Bhagalpur | 412,209 | 30 | 13,366 | Bhagalpur |
| 4 | Muzaffarpur | 396,590 | 26 | 15,005 | Muzaffarpur |
| 5 | Purnia (Purnea) | 312,669 | 60 | 5,188 | Purnia |
| 6 | Darbhanga | 308,011 | 19 | 16,059 | Darbhanga |
| 7 | Bihar (Bihar Sharif) | 297,268 | 23 | 12,649 | Nalanda |
| 8 | Ara (Arrah) | 261,430 | 30 | 8,441 | Bhojpur |
| 9 | Begusarai | 252,008 | 9 | 28,063 | Begusarai |
| 10 | Katihar | 240,838 | 24 | 9,814 | Katihar |
| 11 | Chapra | 213,714 | 16 | 12,601 | Saran |
| 12 | Munger (Monghyr) | 213,303 | 17 | 12,188 | Munger |
| 13 | Saharsa | 156,540 | 21 | 7,408 | Saran |
| 14 | Bettiah | 155,518 | 8 | 19,415 | West Champaran |
| 15 | Hajipur | 147,688 | 19 | 7,519 | Vaishali |
| 16 | Sasaram | 147,408 | 10 | 13,523 | Rohtas |
| 17 | Dehri | 137,231 | 21 | 6,436 | Rohtas |
| 18 | Siwan | 135,066 | 13 | 10,349 | Siwan |
| 19 | Motihari | 126,158 | 16 | 7,702 | East Champaran |
| 20 | Nawada | 118,768 | 5 | 20,909 | Nawada |
| 21 | Bagaha | 112,634 | 46 | 2,405 | West Champaran |
| 22 | Buxar | 110,881 | 5 | 21,488 | Buxar |
| 23 | Sitamarhi | 106,093 | 10 | 10,556 | Sitamarhi |
| 24 | Kishanganj | 105,782 | 30 | 3,512 | Kishanganj |
| 25 | Jamalpur | 105,434 | 10 | 9,899 | Munger |