"We have a football-sized problem now," she said.
The earlier figure, she said, came from a district study completed in 2009.
The new number emerged as the district began work on a long-range facilities plan that could result in closing some of the district's 284 schools, relocating programs to underused buildings, offering space to charter schools, and finding new uses for unneeded buildings.
"School closing is one option, but it's not the only one," Floyd said.
District officials, who will begin the second round of community meetings Feb. 1 to develop the facilities plan, have said it was too early to know how many buildings might be closed or how much savings could be generated from the "right-sizing" plan.
But Deputy Superintendent Leroy Nunery reminded the commission members that half-empty facilities still require the district staff to manage them and provide utilities and security services.
He also said that students who attend small, underutilized schools do not have the opportunities to participate in the range of learning and extracurricular activities that can be offered at larger schools.
Nunery said that the comprehensive facilities plan was the most extensive that the district had undertaken in at least 15 years.
While part of the enrollment decline at district schools can be explained by the 44,000 city students who attend charter schools, Floyd said, the number of school-age children also has declined as the city's population has shrunk.
The district, which has 162,000 students, lost 11,000 in the last five years and is projected to drop to 144,000 by 2015, Floyd said.
Michael Masch, the district's chief financial officer, also gave the School Reform Commission an update on the district's finances on Wednesday.
As he delivered his financial report for the second quarter of the budget year, Masch said that the district's current $3.2 billion budget is balanced.
While sources have told The Inquirer that the district is facing at least a $430 million budget shortfall after July 1, Masch said it was too early to know what the amount could be.
"It is too early to talk about that," he said in a briefing with reporters before the SRC meeting.
He stressed that the district was taking steps to cut costs to ensure that the district's coffers have a bigger financial buffer to help the district cope with the loss of $234 million from the federal stimulus programs that are ending.
Masch said that Superintendent Arlene C. Ackerman on Wednesday had ordered staff to immediately restrict nonurgent spending.
"What is 'urgent'?" Ackerman asked in her e-mail message, obtained by The Inquirer. "Moving forward 'urgent' should be defined as expenses that cannot be deferred."
She said the district will begin by focusing on efficiencies and savings in the central administration offices. Ackerman said she was committed to preserving funds for academic programs and the educational-reform initiatives under her Imagine 2014 academic blueprint.
Contact staff writer Martha Woodall at 215-854-2789 or email@example.com.