The District should boost funding for public education by more than 15 percent — or at least $180 million a year — to ensure that schools have the resources they need to improve student achievement, according to a study commissioned by the D.C. government.

The study calls for raising the city’s basic per-pupil allocation from $9,306 to $11,628, largely to provide better classroom technology and enough teachers, administrators and support workers. It also calls for additional money for students at risk of academic failure and students learning English as a second language and recommends changes meant to ensure equity between charter and traditional schools.

Mayor Vincent C. Gray’s budget proposal for the next school year will be based on the study, administration officials said. But it is likely the recommendations will have to be phased in over a period of several years to accommodate the hefty price tag.

Gray’s budget proposal is to be released in April, and it is not clear which priorities will be funded first nor how much the administration will direct to education.

Deputy Mayor for Education Abigail Smith said she wants to focus resources on the biggest gaps between current and recommended funding, including programs for high school students, students learning English as a second language and students in a new “at-risk” category.

At-risk students are defined as those who are homeless or in foster care or who qualify for food stamps or the welfare program known as Temporary Assistance for Needy Families. High school students who are more than a year older than they should be for their grade level also qualify.

More than 30,000 of the city’s 80,000 students fit that definition. A bill the D.C. Council adopted last year called on the administration to spend more money to help those students. The bill was sponsored by David A. Catania (I-At Large).

In a letter to Gray on Tuesday, Catania asked the city to commit to fully funding the at-risk initiative in fiscal 2015, as the District anticipates hundreds of millions of dollars in additional revenue in coming years. He called it an essential move for closing the city’s achievement gaps between poor and affluent children, among the largest in the nation.

The study recommends that each at-risk student receive the base allocation plus $3,906, which would mean a total expenditure of about $120 million per year. Other jurisdictions that use a similar model for funding at-risk students provide less funding for them. Smith said it’s still not clear how much funding the Gray administration will recommend.

The study is the result of a 2010 D.C. law that requires an examination of the per-pupil funding formula used to distribute taxpayer dollars to schools. Two outside consulting firms looked at spending patterns of successful District schools and hosted panel discussions with dozens of city educators.

The consultants also examined whether the District has been meeting a legal requirement to uniformly fund its charter and traditional schools. They concluded that it has not because, unlike charters, the traditional school system receives heavy subsidies from other city agencies that provide legal services and help with contracts, procurement and facilities maintenance.

“These funding disparities are contrary to D.C. law,” the study said.

Charter advocates, who have complained that the District’s funding is unfair, cheered the conclusion.

“This is the first time ever that the government has admitted that there is inequitable funding in any way, shape or form,” said Robert Cane, executive director of the pro-charter advocacy group ­FOCUS. He said the key question is whether the Gray administration will follow through with the study’s recommendations.

The study recommends funneling all money to schools using the per-pupil formula. But it also suggests that on top of the recommended new $180 million investment, the District may need to continue spending $40 million to subsidize the school system’s maintenance costs.

Smith said that subsidy is likely to shrink over time but may never go away because of the fundamental difference between traditional and charter schools. The school system is legally obligated to serve all children, she said, and must maintain extra space across the District and be ready to accept students at any time.