Philip Frabetti wants to move his wife and two children out of their cramped apartment in the North End, but finding a bigger place that’s affordable has been difficult.

Frabetti, a project manager at Fidelity Investments, said the asking rents of $2,500 or more a month in Newton, Arlington, and Belmont would eat up at least half of his monthly income.

“They’re ridiculously expensive,’’ said Frabetti, 39. “We feel like there’s not a lot of options — the desirable places are out of our reach.’’

Rent and utility costs have risen faster than incomes in recent years, pushing the number of renters who must spend more than half their monthly income on housing to record levels, according to a report by the Harvard Joint Center for Housing Studies. The study, released yesterday, described an “affordability crisis’’ worsened by the recent recession, which eroded family incomes even as record foreclosures pushed more people into the rental market, driving up prices.

As a result, 10.1 million US households, or one in four renters, spend more than half their earnings on rent and utilities. Another one in four households spends one-third to one-half of income on rent and utilities, according to the study.

This squeeze, traditionally concentrated among lower-income families, is increasingly becoming a middle-class problem, according to the study. The percentage of middle-income families using 30 to 50 percent of their income for rent and utility payments more than doubled over the past decade, to 23 percent from 10 percent.

Eric S. Belsky, managing director of the Harvard Joint Center for Housing Studies and an author of the study, called the trend alarming.

“Renter incomes are not keeping up with rising costs,’’ Belsky said. “And if you spend more on rental housing, you have less to spend on other things.’’

For decades, the rule of thumb has been that renters should pay 25 to 30 percent of their income on housing. In 1960, about 12 percent of renters used more than half their income for rent and utilities; by 2000, the share had risen to 20 percent and by 2009, to 26 percent. Soaring energy prices contributed to the increases.

Median asking rent in 2009 was $1,067 a month and median renter income was $31,000 a year nationally, according to the study.

Parts of the study were based on Census Bureau surveys asking residents to estimate the proportion of their income spent on rent. Belsky said researchers reviewed that information for the 100 largest metropolitan areas. In Boston, they found the numbers of renters who said they spent more than half their income on rent jumped to 25 percent in 2009 from 20 percent in 2000.

Ishay Grinberg, chief executive of RentalBeast.com, a Somerville company that lists rentals on its website, said the study might overstate the problem because it did not look at people renting outside large metro areas, who may not be spending as much on rent.

Rents are going up, he said, but for predictable reasons, such as higher property taxes. He added that leeriness about buying real estate means more renters are competing for apartments.

“If there’s a lot more demand than existing supply, prices go up, whether it’s apartments or chocolate,’’ he said. “In this case it’s apartments, and there’s a limited supply.’’

Belsky said low-income renters were most likely to be burdened by high rents because of an acute shortage of affordable housing. Apartment construction in recent years has been geared toward the upper-end market.

Sandra Cassio, a single mother, said the rent on her $1,300-a-month Dorchester apartment consumes about half her monthly paycheck. The 29-year-old cares for her two children and a nephew, and works part time at FedEx for $14 an hour. She also receives child support.

The Dorchester apartment is also $200 more expensive than her last rental in South Boston, which Cassio had to leave when the landlord decided to renovate. She lives frugally to make ends meet; many of her furnishings are secondhand, given to her by friends and family.

“You don’t want to be spending money on things that are not necessities,’’ Cassio said. “There is no ‘I want this.’ There is only ‘I need this.’ ’’

Globe reporter Erin Ailworth contributed to this report. Megan Woolhouse can be reached at mwoolhouse@globe.com.

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