Student Loan Payoff Calculator
Start with the extra you send, or with the date you want it gone.
Key concepts
Payoff date
The month the balance reaches zero. With an extra payment it is today plus the months that path takes. As an input, it is the month you want the balance gone, and the page solves for the extra.
Extra payment
Amount added to the scheduled principal-and-interest payment and applied to principal after that month’s interest.
What this tool does
The extra you send
This calculator models a fixed rate and a level payment. The extra you send can be monthly or once a year, and it goes to principal after interest. Every two weeks is different: half the scheduled payment, 13 full payments a year, not the extra amount times 26. Income-driven plans, a grace period, and a rate that changes after school are not included.
The date you want it gone
Leave the payoff date blank and the cards follow the extra you send. Set the date you want it gone and a second block shows the extra that finishes by then. A second loan stays a second loan. The balances are not added together. The chart draws the standard path and Scenario A.
Level payment, then extra principal
M = P × [r(1+r)^n] / [(1+r)^n − 1] Interest this month = balance × r Principal this month = M − interest + extra
P is the balance you still owe. r is the annual rate divided by 12. n is the term in months. A payoff date uses the level payment that finishes in the months between today and that date, then subtracts M. The difference is the extra. If the date is already past, the page uses one month and says so.
Worked example
28,000 at 5.5% for 10 years has a scheduled payment near 304. Adding 75 extra finishes in month 91 instead of month 120 and saves about 2,198 of interest. From 15 January 2026 that payoff is August 2033. A target of January 2033, 84 months out, needs an extra near 98. The page you open counts from today, so the month name moves. The month count does not.
Common mistakes
- Comparing only the larger monthly check and ignoring interest saved and months saved.
- Typing the original term when years have already passed. Use the balance and the years still left.
- Treating a payoff date as a promise the servicer has agreed to. The extra is the amount this formula needs, applied to principal every month.
Methodology on this page
Fixed-rate amortization for principal and interest only. A monthly extra applies after each month’s interest. Once a year applies the extra in month 12, 24, and so on. Every two weeks pays half the scheduled payment, 13 full payments a year, and does not multiply the extra by 26. Neither path recasts the scheduled payment. The payoff date is today plus the month count. A target date solves for the level extra that finishes in that many months. A second loan is not added to the first. Income-driven repayment is not modeled. The rate you type stays fixed. This is not financial advice.
Read the full FinTools4U methodology →Frequently asked questions
What does the payoff date field do?
It is optional. Leave it blank and the cards follow the extra you type, including the payoff date that extra produces. Set a date and the page shows the extra that finishes by then.
Are income-driven plans included?
No. The payment is the fixed level payment for the balance, rate, and term you type, plus any extra. A payment that changes with income is a different contract.
Does the extra change the scheduled payment?
No. The scheduled payment stays the amount that would finish the term with no extra. The extra is principal on top of it. The last payment is smaller if the balance is less than that sum.
Is this financial advice?
No. The schedule runs in your browser. It does not replace the servicer’s payoff quote or a decision about which balance to pay first.
Sources & further reading
- Federal Student Aid — Repayment plans — Official context for fixed and income-driven plans. This page models a fixed payment only.
- CFPB — Student loans — Borrower-facing tools and explanations. This calculator does not replace a servicer payoff quote.