Student Loan Payoff Calculator
Calculate your monthly student loan payment, total interest, and payoff date — with comparison of standard, extended, and income-driven repayment plans.
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How to use this calculator
- 1
Enter your outstanding loan balance and the interest rate. The 6.52% in the field is the 2026-27 federal fixed rate for new undergraduate Direct Loans (first disbursed 1 July 2026 to 30 June 2027). It is only a starting value: your own loan’s fixed rate governs, so enter the rate on your servicer statement.
- 2
Choose Standard (10 years), Extended (25 years) or a custom number of years. The tool does not check eligibility for any plan.
- 3
Add an extra monthly payment to see how much sooner the loan would be paid off and how much interest that avoids.
- 4
This is a fixed-rate, level-payment model. Income-driven plans, forgiveness and deferment are not included.
Frequently asked questions
What formula does this calculator use?
This tool uses standard loan amortisation: the monthly rate is the annual rate divided by 12, the number of payments is the term in years times 12, and the payment is the balance times r(1+r)^n divided by (1+r)^n minus 1. With a 0% rate it divides the balance by the number of payments. Total interest is the payment times the number of payments, minus the balance.
How is the extra payment modelled?
The tool steps through the loan one month at a time. Each month it adds interest on the remaining balance, subtracts the scheduled payment plus your extra amount, and stops when the balance reaches zero. Time saved is the difference in months from the original term, and interest saved is the original total interest minus the interest in this month-by-month run. The last payment is simply capped at what is owed.
What do the plan choices mean here?
Standard is 10 years, Extended is 25 years and Custom uses the number of years you enter, rounded to the nearest whole month. They differ only in the term used for the calculation. The tool does not check whether you qualify for a particular plan and does not model plans where the payment is tied to income.
Can it handle several loans or changing rates?
No. It takes one balance and one fixed rate. If you have several loans, run each separately; variable rates, capitalised interest, grace periods and deferment are not modelled.
How are zero and unusual inputs treated?
Clearing the rate box counts as 0%, which gives an interest-free loan with $0 total interest rather than the 6.52% starting rate. A balance of zero or less, or a negative custom term, returns a $0 payment, while a custom term of 0 (also what an emptied box becomes) is replaced by 10 years. An extra payment of zero hides the extra-payment lines. Negative rates are treated as zero.
Does the tool show the current federal loan rates?
Only as a starting value. The default 6.52% is the 2026-27 undergraduate Direct Loan rate; the same year’s rates are 8.07% for graduate and professional Direct Unsubsidized Loans and 9.07% for PLUS loans (2025-26 was 6.39%, 7.94% and 8.94%). Rates are set each year and your own loan keeps the fixed rate from the year it was first disbursed, so it may differ. Look at your loan servicer’s statement or studentaid.gov for the rate and balance to enter.
Does it consider the student loan interest deduction or refinancing?
No. The result is a payment and interest schedule only. Tax treatment, refinancing offers and the loss of federal protections after refinancing are outside the calculation.
Student loan payoff: payment, total interest and the effect of extra payments
How the payment is found
The tool converts the annual rate to a monthly rate, multiplies the chosen number of years by 12 and applies the level-payment formula so that the balance reaches zero on the last month. Total paid is the payment times the number of months, and total interest is what remains after subtracting the balance. If you add an extra monthly payment, a second pass runs month by month: interest is added to the balance, the scheduled payment and extra amount come off, and the loop ends when the balance reaches zero. The two runs are then compared for time and interest saved.
Worked examples
The defaults are the figures built into this tool for the 2026-27 award year: a $35,000 balance at 6.52% on the 10-year plan. The payment is $398, total interest is $12,733 and total paid is $47,733. Adding $100 a month brings the payoff time to 7 years 5 months, saves $3,517 of interest and shortens the loan by 2 years 7 months. A larger $60,000 balance at 5% on the 25-year plan has a payment of $351, interest of $45,226 and a total paid of $105,226.
Three terms on one loan
The table keeps the $35,000 balance and 6.52% rate and changes only the term. The monthly payment drops as the term lengthens, but total interest rises much faster than the payment falls, which is the trade-off the repayment-plan choice controls.
| Term | Monthly payment | Total interest |
|---|---|---|
| 10 years (Standard) | $398 | $12,733 |
| 15 years (Custom) | $305 | $19,949 |
| 25 years (Extended) | $237 | $36,028 |
Extra payments, month by month
Extra money goes straight to the balance each month, so interest is charged on a smaller amount the next month. On the default loan, $100 a month turns a 120-month schedule into 89 months. At a 0% rate there is nothing to save in interest, but the term still shrinks: a $20,000 balance on a 5-year custom term has a $333 payment, and adding $100 brings payoff to 3 years 11 months, 1 year 1 month sooner, with $0 of interest either way. That shows how much of the saving in the first example comes from interest and not just from paying faster.
What is not modelled
Income-driven repayment, forgiveness programs, deferment, forbearance, capitalisation of unpaid interest, variable rates and multiple loans are outside the tool. It also does not subtract the interest deduction, compare refinancing or know the rate that applies to a given loan type or year. Because the payment is a level amount for a fixed term, treat it as the baseline against which those alternatives can be measured, and confirm figures with your servicer.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →