Pakistan , [c] officially the Islamic Republic of Pakistan , [d] is a country in South Asia . It is the world's fifth-most populous country with a population exceeding 212.2 million, and has the world's second-largest Muslim population . Pakistan is the 33rd-largest country by area, spanning 881,913 square kilometres (340,509 square miles). It has a 1,046-kilometre (650-mile) coastline along the Arabian Sea and Gulf of Oman in the south and is bordered by India to the east , Afghanistan to the west , Iran to the southwest , and China to the northeast . It is separated narrowly from Tajikistan by Afghanistan's Wakhan Corridor in the northwest, and also shares a maritime border with Oman . Pakistan is the site of several ancient cultures...