Located in the northeastern US, the Commonwealth of Pennsylvania is the 2nd largest of the three Middle Atlantic states and ranks 33rd in size among the 50 states.
The total area of Pennsylvania is 45,308 sq mi (117,348 sq km), of which land occupies 44,888 sq mi (116,260 sq km) and inland water 420 sq mi (1,088 sq km). The state extends 307 mi (494 km) E-W and 169 mi (272 km) N-S. Pennsylvania is rectangular in shape, except for an irregular side on the E and a break in the even boundary in the NW where the line extends N-E for about 50 mi (80 km) along the shore of Lake Erie.
Pennsylvania is bordered on the N by New York; on the E by New York and New Jersey (with the Delaware River forming the entire boundary); on the SE by Delaware; on the S by Maryland and West Virginia (demarcated by the Mason-Dixon line); on the W by West Virginia and Ohio; and on the NW by Lake Erie. The total boundary length of Pennsylvania is 880 mi (1,416 km). The state's geographical center lies in Centre County, 2.5 mi (4 km) SW of Bellefonte.