Taking six years to get a four-year college degree can cost students up to almost $300,000 in tuition, interest on loans, and forgone income and retirement savings, according to a new study from NerdWallet.

Only 40% of college students receive a bachelor’s degree in four years, according to the National Center for Education Statistics. Within six years, 60% of bachelor’s degree seekers will receive a diploma.

Those who take out student loans will have a much bigger college debt to pay off if they need more than four years to earn a bachelor’s degree. In addition, taking one or two “victory laps,” as some students jokingly call extra years, can stunt lifelong retirement savings. NerdWallet’s research shows that students who take six years to obtain a bachelor’s degree could miss out on more than $150,000 in retirement savings compounded over 45 years.

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