Subdivisions
According to the ONS definition the Cardiff Urban Area had the following subdivisions:
| Rank | Urban sub-area name | Population |
| 1 | Cardiff | 292,150 |
| 2 | Penarth | 23,245 |
| 3 | Dinas Powys | 7,653 |
| 4 | Radyr | 4,658 |
| Total | 327,206 |
Read more about this topic: Cardiff Urban Area