When the college math doesn’t add up

A rule of thumb for students is to keep total college debt to no more than the first-year salary for the job they plan to hold after graduation. But at some colleges, the median alumni salary equals the “net cost” that low-income students are paying for just one year at that college, never mind over four years.

National average

SOURCE: Department of Education, 2012-13

Stephanie Redding, Russell Goldenberg / Globe Staff