Repaying a student loan could soon be a little less painful. Starting this week, anyone with a federal student loan can apply for a program that caps monthly payments based on income, and forgives remaining balances after 25 years. Those choosing to work in public service could have their loans forgiven after just 10 years. Eligibility for income-based repayment (IBR) is determined by a person's income and loan size. A calculator at http://www.ibrinfo.org can help borrowers determine their eligibility for the plan, which becomes available Wednesday. "It's a way to borrow for college without going to the poor house," said Lauren Asher, the president of the Institute for College Access & Success, a California-based nonprofit that runs the Project on Student Debt. Monthly payments would amount to less than 10 percent of income for most of the estimated 1 million people expected to enroll, experts say. Payments would never exceed 15 percent of any income above about $16,000 a year (or 150 percent of the poverty level). Those who earn less than $16,000 would not have to make any monthly payments. The new payment option is intended to provide relief for those who earn modest salaries and struggle under the weight of student loans for years on end.