Pakistan has launched its first national census in nearly two decades amid tight security.
Asif Bajwa, Pakistan's chief census officer, said the count would be completed by May 15.
He said the survey would for the first time include an estimated 1 million Afghan refugees living in Pakistan and also transgender people.
Around 200,000 soldiers will escort the civilian staff to collect door-to-door data for the housing and population survey.
Pakistan, the sixth most populous country in the world, last conducted a census in 1998, when the population was around 180 million. It is believed to have since risen above 200 million.
Previous attempts to hold a national census were shelved due to insecurity in Pakistan, where militant groups have waged a bloody conflict against the Islamabad government.
The count will be the basis for revising political boundaries, parliamentary seat allocations, and federal funding as the country prepares for a general election next year.