College students and graduates, and their families, owe a combined $1.6 trillion in student loans, according to federal data. About 17% of U.S. adults have outstanding student loan debt, averaging more than $35,000 per person. That level of debt has caused people to wonder if college is a sound investment.

Researchers at Georgetown University’s Center on Education and the Workforce say it is. A 2019 analysis found that workers with bachelor’s degrees make 80% more than workers with only a high school diploma. That study and a 2022 follow-up study found that some colleges have greater return on investment—the money spent on tuition and other expenses—than others.

To help future students make a more informed decision, the research team behind the studies ranked 4,500 colleges, determining the best financial options. To do this, the team used data collected by College Scorecard.

The study ranks schools by the net present value, a measure of the projected earnings of an investment against the anticipated costs, both in today’s dollars and taking into account discounting interest rates, to determine whether an investment is worth making. Colleges were then ranked by the highest 40-year return on investment, with ties broken by the 10-year return.

Stacker looked at the public colleges with the best return on investment, highlighting information like graduation rates, net price, and median debt. This story only considers four-year, public colleges that predominantly grant bachelor’s degrees.

Here’s a breakdown of some key factors in the researchers’ calculations.

– 40-year NPV: What the sum of all earnings 40 years after enrollment is worth today, adjusted for the school’s education cost.

– Median earnings after 10 years: The typical annual salary 10 years after enrollment.

– Net price: The average price students pay per year after scholarships and financial aid, including books and living expenses.

– Graduation rate: The share of students who complete bachelor’s degrees within six years.

– Median debt: The typical amount of student debt graduates from this school hold.