Public colleges with the best bang for your buck

20-year return on investment : $769,600
Annualized return: 13.9%
Total 4-year cost of attendance: $129,900

Despite being one of the most expensive public schools on the PayScale list, UC Berkeley is also one of the best investments.

This highly-ranked research university is a recruiting hotspot for Silicon Valley tech firms. The tendency for UC Berkeley students to stay in that area post-graduation may account for some of the school's high return on investment, said Frank.

"It has a great reputation," she said. "But a lot of people do tend to stay in California, and the cost of living and salaries there are ultimately going to be a bit higher."

First published March 5, 2015: 1:50 PM ET

Source: PayScale
Based on employee survey data, PayScale calculated total median pay for a school's undergraduate alumni over a 20-year period and compared it to the median pay for a high school graduate over 24 years. The return on investment (ROI) in 2014 dollars was determined by taking the difference between those median pay figures and subtracting the in-state cost of attending the school in 2014 -- including tuition, room and board, and other costs -- and adjusting for scholarships and grants. The annualized ROI is calculated by dividing the earnings differential by the total cost and represents the percent of expected ROI received each year after graduation. Unlike in previous PayScale reports, the earnings differentials in this report do not take into account graduation rates. Alumni who attended graduate school or other higher education were excluded.

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