The cost of college in the United States rose sharply for the 2011-2012 school year, continuing a long pattern in which public school increases outpaced private school hikes and both eclipsed the average rate of inflation by significant amounts, the College Board reported Wednesday.

At public 4-year schools, average tuition and fees rose 8.3 percent to $8,244 for in-state students and 5.7 percent to $20,770 for out-of-state students, not including room, board, or extra expenses like travel, laptops and midnight pizzas.

Private nonprofit four-year schools raised their tuition and fees by 4.5 percent, to an average of $28,500, according to the study, Trends in College Pricing 2011, released by the College Board Advocacy & Policy Center. The Consumer Price Index increased 3.6 percent between July 2010 and July 2011, the study noted.

In-state tuition and fees for public two-year colleges averaged $2,963, an 8.7 percent increase from the previous year.

So-called net prices -- the amount that families pay after receiving grant aid and taking advantage of tax credits -- have increased by an average of about 1.4 percent a year for the last five years at public four-year schools, the College Board said. Those increases made college less affordable, as average family inflation-adjusted incomes have fallen in the decade between 2000 and 2010, the College Board said.

While the importance of a college degree has never been greater, its rapidly rising price is an overwhelming obstacle to many students and families, said College Board President Gaston Caperton.

Financial aid rose as well, the College Board said in a companion report, but not enough to cover increases in tuition and fees at four-year public schools. In the 2010-2011 year, undergraduate students received an average of $12,455 per full-time equivalent student in financial aid, including $6,539 in grant aid, $4,907 in federal loans, and $1,009 in a combination of tax credits and deductions and federal work-study jobs.

Many students supplement that with private loans, a figure that the College Board estimated at about $6 billion in total volume. In a separate development, President Barack Obama unveiled a program on Tuesday that he said would help some 1.6 million student borrowers lower their student loan payments.

College costs are still outpacing family incomes and available aid, said Lauren Asher, president of the Institute for College Access & Success, an advocacy group.

The maximum Pell Grant covers barely a third of the full cost of four years of college and we have more people with student loans than ever before, and they are borrowing more than ever.

Asher has emphasized the bottom line cost of college, including all of those extra expenses such as travel and supplies, and noted that they make college even less affordable than the tuition, room, board and fees figures upon which the College Board focuses.

Beginning Saturday, U.S. colleges are required to post net price calculators on their web sites. These calculators are supposed to go beyond sticker prices to include estimates of total cost of attendance, including the extras, as well as estimates of typical aid paid to students at the school.

Advocates do advise applicants to look for those calculators and use them in weighing how much it would cost to attend individual schools.

But Asher says there are already some problems with them. Some colleges have buried the calculators so they are difficult to find, she said. Others have made the calculators extremely complex and may ask dozens of questions of students. She suggests that students using the calculators focus on net prices and not other figures, such as after-loan out of pocket costs, that some schools are posting.

Caperton suggested that the board's efforts to analyze college affordability and price changes were complicated by the variability of prices from one state to another.

The large and well publicized increases in the California state system had a big impact on the averages; that state enrolls about 10 percent of the nation's full-time public four year college students and raised in-state fees 21 percent and 37 percent for full-time public two-year college students. Without the California figures included in its data, that 8.3 percent public four-year in-state school increase would have been 7 percent, and the 8.7 percent increase logged for two-year public schools would have been 7.4 percent.