“We run the risk of talking about a district that is no longer financially able to operate,” Dr. Hite told a noisy meeting of about 450 parents, students and teachers at Martin Luther King High School in the Germantown neighborhood on Dec. 19, at which district officials were trying to sell their plan.

Although the district has been able to borrow enough to operate this year, it has reached its credit limit, Dr. Hite said. “We no longer have the ability to borrow that kind of money going forward,” he said.

Other large cities, including Chicago, Detroit and Washington, are also considering school closings because of declining enrollment, competition from charter schools and overcapacity, said Michael Casserly, the executive director of the Council of the Great City Schools, an advocacy group for urban public schools.

But Philadelphia has been hit hard by state education financing that has been among the lowest per student of any major city, Mr. Casserly said. “The state’s historical lack of spending has had an eroding effect on the district,” he said.

The proposed cuts — which are scheduled to be voted on in March by the School Reform Commission, a state organization that oversees the district — have ignited angry protests from teachers, students and parents. They argue that children, particularly in their elementary years, should not be forced to attend school outside their neighborhoods; that academic improvements would be disrupted; and that students attending new schools would be victimized because of longstanding inter-neighborhood rivalries.