Loan payoff maths

Student Loan Payoff Planner

Enter your loan balance, interest rate and monthly payment to see exactly how long payoff will take, how much interest you'll pay, and your estimated payoff date.

—Months to payoff
—Estimated payoff date
—Total interest paid
—Total amount paid
Enter your loan details above.

Calculated on your device. Nothing is uploaded or stored on a server.

How to use the student loan payoff planner

Type in your current balance, your loan's annual interest rate (APR) and the fixed monthly payment you plan to make. The planner simulates your loan month by month, applying interest first and the remainder to principal, exactly the way a standard amortizing loan works.

How student loan payoff is calculated

Each month, interest accrues on your remaining balance at your APR divided by 12. Whatever is left of your payment after that interest reduces your principal. As the balance shrinks, less of each payment goes to interest and more goes to principal, which is why payoff accelerates near the end. If your payment doesn't exceed the interest charged each month, the balance will never decrease — the planner will warn you if that's the case.

Paying extra helps a lot

Even a small increase to your monthly payment can cut months (and interest) off your payoff timeline, because more of every extra dollar goes straight to principal.

This is an estimate

Real servicers may compound interest daily or apply payments slightly differently. Use this as a planning guide, not an official payoff quote.

Student loan payoff planner FAQ

Common questions, answered.

How is the payoff time calculated?

The planner simulates your loan month by month: each month it charges interest on the remaining balance at your APR divided by 12, then applies the rest of your payment to principal, repeating until the balance reaches zero.

What if my payment doesn't cover the interest?

If your monthly payment is less than or equal to the interest charged that month, your balance will never go down. The planner detects this and tells you to increase your payment.

Does this include loan fees or origination charges?

No. This tool models interest and principal only. Add any fees separately to get your true total cost.

Can I use this for multiple loans at once?

Enter one loan at a time. For several loans, run each one separately, or combine them into a single average rate and total balance for a rough estimate.

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