Fixed versus income-driven repayment
This model has fixed monthly payments. Income-driven federal repayment depends on additional income, household and program information; use the official Federal Student Aid simulator to assess those plans.
Loans
Student Loan Calculator
Calculate fixed student loan payments, interest and payoff time with extra monthly payments. Compare refinancing at an entered new rate, term and financed fee.
Student loan payoff time with extra payments
7 yr 2 mo
Required baseline monthly payment
$333.06
Planned monthly payment with extra
$433.06
Interest with extra payments
$6,921.10
Interest saved by extra payments
$3,046.28
Months saved
2 yr 10 mo
Refinance monthly payment
$318.20
Refinance savings vs baseline after fee
$1,783.80
Result comparison
Required baseline monthly payment: $333.06Required baseline monthly payment · $333.06
Planned monthly payment with extra: $433.06Planned monthly payment with extra · $433.06
Interest with extra payments: $6,921.10Interest with extra payments · $6,921.10
Interest saved by extra payments: $3,046.28Interest saved by extra payments · $3,046.28
Refinance monthly payment: $318.20Refinance monthly payment · $318.20
Refinance savings vs baseline after fee: $1,783.80Refinance savings vs baseline after fee · $1,783.80
Required baseline monthly paymentRefinance savings vs baseline after fee
Hover, tap or focus a column to see its exact value.
Student loan payoff with extra payments
Detailed values use the same assumptions as the summary above.
| Month | Payment | Interest | Principal | Balance |
|---|---|---|---|---|
| 1 | $433.06 | $150.00 | $283.06 | $29,716.94 |
| 2 | $433.06 | $148.58 | $284.48 | $29,432.46 |
| 3 | $433.06 | $147.16 | $285.90 | $29,146.56 |
| 4 | $433.06 | $145.73 | $287.33 | $28,859.23 |
| 5 | $433.06 | $144.30 | $288.77 | $28,570.47 |
| 6 | $433.06 | $142.85 | $290.21 | $28,280.26 |
| 7 | $433.06 | $141.40 | $291.66 | $27,988.60 |
| 8 | $433.06 | $139.94 | $293.12 | $27,695.48 |
| 9 | $433.06 | $138.48 | $294.58 | $27,400.90 |
| 10 | $433.06 | $137.00 | $296.06 | $27,104.84 |
| 11 | $433.06 | $135.52 | $297.54 | $26,807.30 |
| 12 | $433.06 | $134.04 | $299.02 | $26,508.28 |
A monthly mathematical model, not an income-driven repayment or forgiveness estimate. Federal-loan benefits, eligibility, daily accrual and actual servicer allocation rules can affect outcomes.
Calculation method
Formula and method
P includes principal plus accrued interest you choose to capitalize. The monthly rate r is annual nominal interest / 100 / 12. At zero rate, the baseline payment equals P/n.
Detailed guide
Compare student loan payoff and refinancing
Enter current principal, the fixed rate and remaining term. If unpaid interest will be capitalized before repayment begins, enter that amount separately. The calculator shows the required payment and how extra monthly payments reduce repayment time and interest.
Refinance comparison uses the same starting balance plus the entered financed fee. A lower payment from a longer term can still increase total interest; compare lifetime cost as well as the installment.
Formula and method
Payment = P × r / (1−(1+r)^−n); refinance savings = current interest − new interest − fee
P includes principal plus accrued interest you choose to capitalize. The monthly rate r is annual nominal interest / 100 / 12. At zero rate, the baseline payment equals P/n.
Extra payments are applied after monthly interest and the scheduled payment. The final installment is limited to the remaining balance and interest. Refinancing is compared with the current loan without extra payments.
Using the results
Federal-loan refinancing
Refinancing a federal loan into a private loan can change available protections and repayment options. A modeled interest saving alone does not assess those benefits.
Frequently asked questions
Can I calculate extra-payment savings?
Yes. Enter an extra monthly amount to see a shorter term, interest saved and a monthly payoff schedule.
Does this use daily student-loan interest?
No. It divides a fixed nominal annual rate into monthly periods. Actual daily interest and payment dates can differ from the schedule.
Can I compare refinancing?
Yes. Enter a new rate, term and financed fee. The result compares total borrowing cost with the existing loan’s baseline schedule.
Data sources
These sources explain the concepts used in the calculation. Check the applicable contract or issuer documents for your actual parameters.
Updated: October 1, 2026
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