New York City uses a formula to estimate how many students should fit in each public school in the city. The formula is primarily based on target class sizes per grade and the number of available classrooms in a school.

Under this formula, some schools are currently far under or over their estimated capacity.

Number of public schools by enrollment as a percentage of capacity

This year, the city is trying to improve its formula by excluding more specialized rooms like art studios and counseling offices from its calculation of available classroom space. That means that the estimated capacity of many schools has decreased and overcrowding looks worse than before.

Percent of schools that are overcrowded
Percent of students in overcrowded schools

The new formula has had a particular impact on elementary schools. Almost 30,000 more elementary school students are attending overcrowded schools than under the previous formula.

Percent of elementary schools that are overcrowded
Percent of elementary school students in overcrowded schools
Data from the NYC Department of Education's "Enrollment, Capacity, & Utilization Report" 2013-2014 and 2014-2015.

School Capacity