There's no single, readily available, completely accurate figure for the total number of schools in Pakistan. The data collection process is complex and varies depending on the level of education (primary, secondary, higher secondary, etc.), the type of school (public, private, religious), and the reporting body. Different government ministries and organizations may have slightly different counts.
To find an estimate, you would need to consult multiple sources, such as the Ministry of Education, provincial education departments, and various educational surveys conducted in Pakistan. Even then, the number would be an approximation, and its accuracy would depend on the comprehensiveness of the data collected.