The graph below ranks each Pennsylvania County by total residents according to the 2012 census estimates.
Pennsylvania total population by county
| County | Total Population |
| Philadelphia |  1,548,647 |
| Allegheny | 1,229,912 |
| Montgomery | 808,946 |
| Bucks | 626,377 |
| Delaware | 560,699 |
| Lancaster | 526,436 |
| Chester | 506,190 |
| York | 437,411 |
| Berks | 412,948 |
| Westmoreland | 363,233 |
| Lehigh | 354,746 |
| Luzerne | 321,423 |
| Northampton | 299,371 |
| Erie | 280,823 |
| Dauphin | 269,797 |
| Cumberland | 239,164 |
| Lackawanna | 214,428 |
| Washington | 208,451 |
| Butler | 185,084 |
| Beaver | 170,274 |
| Monroe | 168,436 |
| Centre | 155,100 |
| Franklin | 151,372 |
| Schuylkill | 147,372 |
| Cambria | 141,541 |
| Fayette | 135,668 |
| Lebanon | 135,406 |
| Blair | 127,004 |
| Lycoming | 117,317 |
| Mercer | 115,629 |
| Adams | 101,610 |
| Northumberland | 94,560 |
| Lawrence | 89,766 |
| Indiana | 88,143 |
| Crawford | 87,687 |
| Clearfield | 81,494 |
| Somerset | 77,115 |
| Armstrong | 68,367 |
| Columbia | 66,852 |
| Carbon | 65,016 |
| Bradford | 62,800 |
| Pike | 56,782 |
| Venango | 54,283 |
| Wayne | 51,734 |
| Bedford | 49,354 |
| Mifflin | 46,790 |
| Huntingdon | 45,888 |
| Perry | 45,724 |
| Union | 45,021 |
| Jefferson | 44,857 |
| McKean | 43,254 |
| Susquehanna | 42,683 |
| Tioga | 42,595 |
| Warren | 41,188 |
| Snyder | 39,751 |
| Clinton | 39,738 |
| Clarion | 39,459 |
| Greene | 38,088 |
| Elk | 31,648 |
| Wyoming | 28,193 |
| Juniata | 24,913 |
| Montour | 18,490 |
| Potter | 17,635 |
| Fulton | 14,748 |
| Forest | 7,659 |
| Sullivan | 6,437 |
| Cameron | 4,948 |