Student Loan Payoff Calculator
See how long your student loan payment will really take and how much interest it costs, then see what it takes to be done in 5 or 10 years.
How long will my payment take?
How this calculator works
Federal and private student loans both charge interest the same basic way most installment loans do: each month, interest adds up on whatever balance is left, and whatever you pay beyond that interest chips away at the principal. This calculator simulates your loan month by month at the payment you enter, tracking the balance until it hits $0, and adds up every dollar of interest along the way. It also shows two fixed-payment plans (5 years and 10 years) using the standard amortization formula, the same math lenders use to set a payment that clears a balance by an exact date: payment = balance × monthly rate ÷ (1 − (1 + monthly rate)^−number of months); at 0% interest it's simply balance ÷ months.
Worked example
A $30,000 balance at 6% interest, paying $350 a month, takes about 113 months (9.4 years) and costs $9,271 in interest, for a total of $39,271 paid. To be done in exactly 5 years you'd need $579.98/month ($4,799 interest). To be done in 10 years you'd need $333.06/month ($9,967 interest), a lower monthly payment but more total interest because it's spread out longer.
Frequently asked questions
Why does a smaller payment sometimes barely move the balance?
If your payment is close to that month's interest charge, most of it is covering interest and very little goes to principal, so the balance shrinks slowly. If the payment is at or below the interest charge, the balance never goes down at all, and this calculator will tell you that directly along with a payment that would actually clear it.
Does this handle income-driven repayment plans?
No. Income-driven plans change your payment as your income changes and can involve forgiveness after a set number of years, which is a different kind of math than a fixed monthly payment. This calculator is built for a standard fixed-payment payoff, federal or private.
Should I pay extra toward my student loan or save instead?
That depends on your interest rate, any employer savings match, and your own priorities, which this calculator doesn't weigh in on. Use the numbers above to see exactly what extra payments are worth in time and interest saved, then decide what fits your situation.
Assumptions & sources
- Fixed interest rate for the life of the balance, no new charges, no fees, no missed or late payments, no deferment or forbearance periods.
- Interest is calculated monthly on the remaining balance (annual rate ÷ 12).
- The 5/10-year plans use the standard fixed-payment amortization formula: payment = balance × monthly rate ÷ (1 − (1 + monthly rate)^−months).
Educational estimates, not financial advice.