In the last two years, California, Georgia, Nevada, Ohio, Utah and Wisconsin have loosened legal restrictions on class size, and Idaho and Texas are considering doing so, The New York Times reported Sunday.
It is a reversal of a decades-long trend. Since the 1980s, teachers have embraced research indicating smaller classes lead to higher achievement.
In Los Angeles, 11th- and 12th-grade English and math classes have grown to 43 students on average. Cash-strapped Detroit is considering raising high school class sizes to 60 students.
Rachael Maher, a math teacher in Charlotte, N.C., said she has seen her seventh-grade classes grow from 25 students to 31.
"They say it doesn't affect whether kids get what they need, but I completely disagree," she said. "If you've gained five kids, that's five more papers to grade, five more kids who need makeup work if they're absent, five more parents to contact, five more e-mails to answer. It gets overwhelming."
Randi Weingarten, president of the American Federation of Teachers, said surveys show parents care more about small classes than anything else but school safety.