How extra payments work
Student loans charge interest on the outstanding balance, so any amount you pay beyond the required payment reduces principal and every future month's interest. A $35,000 loan at 6% over 10 years has a standard payment of about $389 and costs around $11,600 in interest. Adding $150 a month clears it more than three years early and saves about $4,200.
When you pay extra on US federal loans, ask the servicer to apply the extra to principal and not to advance your due date, and target the highest-rate loan first if you have several.
Should you pay early?
It depends on the rate and your other options. Paying off a 6% to 8% loan early is a guaranteed return at that rate. For low-rate loans, investing extra money may grow faster over time. If you might qualify for Public Service Loan Forgiveness or an income-driven plan with forgiveness, paying early can reduce the amount forgiven, so check your plan first.
A longer plan costs more than it looks
Stretching the term lowers the monthly payment but raises the total cost sharply. The same $35,000 at 6% costs about $389 a month and $11,600 of interest over 10 years. Over 20 years the payment falls to about $251, but interest more than doubles to roughly $25,200, and over 25 years it is about $226 a month with around $32,700 of interest, almost as much as the original loan.
If a lower payment is what keeps your budget working, a longer plan is a reasonable choice, and you can still pay extra whenever you have spare money. Federal loans have no prepayment penalty, so you keep the flexibility either way.
Common questions
How much interest will I pay on $35,000 of student loans?
At 6% on a standard 10-year plan, about $11,600. On a 25-year plan the same loan costs roughly $32,700 in interest.
Is it smart to pay off student loans early?
Usually for higher-rate private or federal loans. Check forgiveness programs before paying extra on federal loans.
How do I make sure extra payments go to principal?
Tell your servicer in writing or in your online account to apply extra payments to principal, highest rate first.
Should I refinance my student loans?
Refinancing federal loans into private ones can lower the rate but removes federal protections like income-driven repayment.
This calculator gives estimates for planning. Real returns, rates and prices change, so treat the result as a guide rather than a promise. Read how we build and check our calculators.