Before you send a single extra dollar
Extra payments are powerful — but on student loans, order of operations matters more than enthusiasm. First: are you on a forgiveness track (PSLF, income-driven forgiveness)? If yes, extra payments may be pure loss — run, don’t walk, to a repayment-plan comparison before prepaying. Second: is your servicer applying extra amounts to principal, not advancing your due date? That single setting is the difference between the savings shown above and an interest-free loan you’ve made to your servicer.
Cleared those two? Then the math here is exact: every extra dollar goes straight to the balance, shortens the loan, and saves its interest rate, guaranteed. Several loans? Aim the extra at the highest rate first — our snowball vs. avalanche comparison quantifies the difference with your actual loans.
What this calculator assumes
Simple monthly accrual at a fixed rate (federal loans accrue daily, but the monthly approximation is within a rounding error), payments on time, no capitalization events, and no forgiveness. If your payment barely covers interest — common on income-driven plans early in a career — the calculator will tell you rather than pretend a payoff date exists.
Frequently asked questions
Should I pay extra on federal student loans?
It depends on your track. If you’re pursuing Public Service Loan Forgiveness or expect meaningful forgiveness on an income-driven plan, extra payments can be money donated to a balance that would have been forgiven anyway. If you’re on the standard 10-year plan with no forgiveness in sight, extra payments work exactly as this calculator shows.
Pay off student loans or invest?
Compare the loan rate to a realistic investment return. Below ~5%, math slightly favors investing (especially with a 401(k) match available); above ~7%, the guaranteed saving from prepayment is hard to beat; in between, it’s a temperament call. Private loans at 8–14% are almost always worth attacking first.
How do I make sure extra payments reduce principal?
Tell your servicer explicitly to apply extra amounts to the principal of a specific loan, not to “advance the due date.” Advanced due dates feel like progress but just prepay future bills without cutting interest. Most servicer portals have a setting or checkbox — verify on the next statement.
Which loan should I target first if I have several?
Highest interest rate first (avalanche) saves the most — typically private loans, then unsubsidized federal. If your servicer splits your payment across all loans automatically, direct only the extra amount at the target. Compare strategies with our debt snowball vs avalanche calculator.
Is refinancing student loans a good idea?
For private loans, often — a lower rate is pure win if the fees are low. For federal loans, refinancing into a private loan permanently gives up income-driven repayment, deferment protections, and any forgiveness path. Only refinance federal debt if your income is secure and you’d never use those safety nets.