Schools are now at 68 percent capacity, and under the plan that figure would increase to 80 percent, he said.
Increasingly over the last decade, parents have chosen to send their children to charter schools, leaving the district with fewer resources.
Hite, in his announcement at district headquarters, said the district would try to achieve two goals as it moves forward: improving academic results and ensuring "the financial sustainability, stability and survival of the Philadelphia School District."
The district will hold informational community meetings about Hite's recommendations beginning Saturday. The SRC is expected to vote in March on the plan.
Hite acknowledged that the announcement would be "shocking, painful, emotional and disruptive" to the city.
Public school advocates organized a protest Thursday afternoon outside district headquarters on Broad Street near Spring Garden, a couple of hours after Hite's announcement. Many critics see a report from consultants, the Boston Consulting Group, as having forced the school closings on the district.
Others were frustrated that they were not included in the decision-making process.
Rosemarie Foster Hatcher, president of the Philadelphia Home and School Council, said, "we were not at the table from the beginning, which we should have been. It's our children. We have the say in their education . . . We were not involved and we're very upset about that."
Union leaders said Hite did not discuss the closure list with them before the announcement.
Jerry Jordan, president of the Philadelphia Federation of Teachers, said he was "furious" to find out early Thursday that a list had been sent to all PFT members.
Hite had told Jordan on Wednesday afternoon that he felt "uncomfortable about sharing" the list with the labor leader because it hadn't been finalized. By 5:30 p.m. Wednesday, some reporters had received an embargoed copy of the list from the district.
"I have never ever known an administration in my career to operate in such a disingenuous manner," Jordan said.
"The distances that kids are going to have to travel are enormous in some cases," Jordan said. "The entire process has been problematic. Parents were never informed about this. Teachers were never informed about this."
But at City Hall, Mayor Nutter said Hite has his "full and unequivocal support."
"No one ever wants their school or a school or an institution in their neighborhood to close. But we can't keep them open if they're not either providing a high-quality education in that facility or if parents are making decisions not to send that child to that particular school," Nutter said.
Echoing a sentiment expressed by Hite, Nutter said such tough action has been long needed.
"You cannot kick the can down the road any further," he said. "These are decisions that could have been made and should have been made many years ago."
Mark Gleason, executive director of the Philadelphia School Partnership, said shuttering lower-performing and under-capacity schools would enable the district to invest in quality teachers and instruction.
"Critics of progress may say this is about privatizing public education. In fact, these closings are the by-products of parents choosing to leave failing public schools for better ones," Gleason said. He cited Strawberry Mansion High School, saying that 75 percent of students in that neighborhood attend other schools.
"That leaves Strawberry Mansion with too few resources to properly educate the students who remain," he said.
City Councilwoman Jannie Blackwell, who heads Council's Education Committee, said she would schedule a hearing on the closings to assess its impact.
"We're upset about it," she said. "It's a big issue and we're going to have a tough year ahead of us."
Hatcher also lamented the timing of the announcement.
"The timing is off. It's the holiday time," she said. "Families should be joyous and celebrating. Instead, they'll be mourning, 'Oh my god, where am I going to send my children?' "
- Staff writers Jan Ransom
and Sean Collins Walsh
contributed to this report.
On Twitter: @ReginaMedina