Hillary Clinton has unveiled an interactive tool that lets families calculate how much they would save under her proposal to eliminate tuition at public colleges and universities, a plan that new research says would swell the rolls at state schools while draining enrollment at private ones.

The calculator is rooted in the Democratic presidential candidate’s pitch that in-state tuition be free for students from household earning less than $125,000 a year. Families can see whether they’d benefit from the plan by plugging in their annual income, where they live and what type of college their child plans on attending.