Columns: Code | County | Former Province | Area (km 2 ) | Population Census 2009 | Capital
18 | Nyandarua | Central | 3,107.7 | 596268 | Ol Kalou | 19 | Nyeri | Central | 2,361.0 | 693558 | Nyeri | 20 | Kirinyaga | Central | 1,205.4 | 528054 | Kerugoya / Kutus | 21 | Murang'a | Central | 2,325.8 | 942581 | Murang'a | 22 | Kiambu | Central | 2,449.2 | 1623282 | Kiambu