Student Loan Payment Calculator
Estimate a fixed monthly payment or a payoff timeline, then see how an extra monthly principal payment changes interest and time to payoff.
Loan assumptions
Required. Enter $1 to $10,000,000 using U.S. decimal notation.
Required. Enter 0% to 50%; fixed-rate monthly amortization is assumed.
Required in this mode. 1 month to 50 years, rounded to the nearest month.
Required in payoff-date mode. It must be high enough to reduce principal.
Optional. Enter $0 to $1,000,000; modeled as recurring principal reduction.
Required. Used only to turn the payoff month count into a calendar date.
Live results
Required monthly payment
$325.58
Before the optional extra monthly payment.
Estimated payoff date
October 2033
Based on the current payment plus any extra amount.
Total monthly payment
$425.58
Payoff time
7 yr 2 mo
Total interest
$6,316.14
Total repaid
$36,316.14
With $100.00 extra each month, this example pays off 34 months sooner and saves $2,753.32 in interest.
Extra-payment impact
Baseline interest
$9,069.46
Interest saved
$2,753.32
Baseline payoff
10 yr
Time saved
34 mo
Balance over time
Compare the remaining balance under the baseline payment with the balance after your recurring extra payment.
In the demonstration, the extra $100.00 monthly payment reaches a zero balance 34 months earlier.
Accessible data summary: baseline payoff is 120 months; accelerated payoff is 86 months.
Year-by-year repayment summary
| Year | Payments | Interest | Principal | Ending balance | Baseline balance |
|---|
Rows group up to 12 monthly payments from the current plan. The full month-by-month schedule is included in the Excel workbook.
How to use this student loan payment calculator
What this calculator does
This calculator models a single fixed-rate student loan with monthly interest and regular monthly payments. In Monthly payment from term mode, it solves for the level payment needed to amortize the current balance over the remaining term. In Payoff date from payment mode, it starts with an existing payment and simulates how many months are needed to reach a zero balance. In both modes, it then applies the optional recurring Extra monthly payment and compares the resulting payoff time and interest cost with a baseline that has no extra payment. It is a planning estimate, not a servicer statement or a determination of federal repayment-plan eligibility. Federal Student Aid's Loan Simulator guidance explains why official repayment-plan estimates can depend on additional borrower and loan details.
When to use it
Use the calculator when you want to budget for a fixed payment before repayment begins, test whether a higher recurring payment could shorten your payoff, compare the interest cost of paying only the scheduled amount versus paying extra, or estimate the calendar month when an existing fixed payment would eliminate the balance. If you have several loans with different rates, income-driven payments, changing rates, deferment, capitalization events, or forgiveness rules, model each loan separately or use your official servicer and Federal Student Aid tools.
How to calculate
- The calculator opens with a ready-to-use demonstration: a $30,000 balance, 5.5% annual rate, 10-year term, $100 extra monthly payment, and September 2026 first payment month. The demonstration is already calculated and its Excel workbook is immediately available.
- Choose What would you like to calculate? Use Monthly payment from term when you know the remaining term. Use Payoff date from payment when you know the monthly amount you are already paying.
- Replace the demonstration values with your loan details. Results, the line chart, and the yearly table update live. Read the baseline comparison to see whether the extra payment meaningfully changes the result.
- Select Download Excel to export the current validated assumptions, summary, annual comparison, and full monthly schedule. Reset clears the demonstration and calculated content; the Excel button then stays unavailable until you enter a complete valid scenario again.
Input guide
What would you like to calculate? is required and accepts one of the two modes described above. Changing it swaps the required term field for the required payment field. Current loan balance is the unpaid principal being modeled, entered in U.S. dollars from $1 to $10,000,000; for example, $30,000. Do not enter a future loan amount or combine balances with materially different rates unless a single blended-rate model is truly appropriate. Annual interest rate is a required percentage from 0% to 50%; 5.5% means 5.5, not 0.055. Most federal student loans have fixed rates, while private-loan terms can differ; the Consumer Financial Protection Bureau summarizes how student loan interest rates work.
Remaining loan term is required in monthly-payment mode and accepts approximately one month through 50 years; the entered years are converted to the nearest whole month. A longer term usually lowers the required payment but increases total interest. Current monthly payment is required in payoff-date mode and is entered in dollars; it must exceed the monthly interest enough to reduce principal, so a payment that merely covers or falls below interest is rejected. Extra monthly payment is optional, from $0 to $1,000,000; for example, $100. This model assumes the extra amount is applied to principal each month after scheduled interest. Real allocation instructions matter: CFPB explains that student loan payments are generally applied to fees, then interest, then principal, and that borrowers making extra payments may need to give servicer instructions. First payment month is required in YYYY-MM form and controls only the displayed payoff date, not the interest formula.
Output guide
Required monthly payment is the fixed baseline payment calculated from balance, rate, and term in monthly-payment mode. Estimated payoff date is the month containing the final simulated payment; in payoff-date mode it is the primary result. Total monthly payment equals the baseline/current payment plus the recurring extra payment, except that the final payment can be smaller. Payoff time is the number of simulated monthly payments expressed in years and months. Total interest is the sum of monthly interest in the plan with the selected extra amount, and Total repaid is principal plus that interest. Baseline interest and Baseline payoff show the same loan without the extra payment. Interest saved and Time saved are comparisons against that baseline; both are zero when there is no extra payment. The Balance over time chart plots baseline balance and the balance with extra payment on the same dollar scale. The yearly table's Payments, Interest, Principal, Ending balance, and Baseline balance columns aggregate the same canonical monthly schedule used by the results and workbook.
Worked example
With the demonstration values, the monthly rate is 5.5% ÷ 12 and the 10-year term is 120 payments. The standard amortization formula produces a required payment of $325.58. Paying an additional $100.00 makes the planned monthly amount $425.58. The modeled loan is then repaid in 86 months (7 years 2 months), with the final payment occurring in October 2033. Total modeled interest falls from $9,069.46 on the 120-month baseline to $6,316.14, a savings of $2,753.32, while payoff arrives 34 months sooner. Those values are the same first-open figures used by the table, chart, and export workbook.
Learn more
For federal loans, payment structures and eligibility can differ from this fixed-payment model. Federal Student Aid describes traditional and other repayment choices in its student loan repayment preparation guide. Use official loan data and servicer instructions before changing a real repayment strategy.
How the payment and payoff math works
For a fixed-rate loan with a positive monthly rate, the required level payment is calculated from the current principal, the monthly interest rate, and the number of monthly payments. If the annual rate is zero, the payment is simply the balance divided by the number of months. The calculator keeps full numerical precision during the model and rounds only for display and spreadsheet formatting.
Each month, interest is calculated on the remaining balance. The scheduled payment plus any recurring extra payment first covers that modeled interest; the rest reduces principal. The final payment is capped at the amount needed to bring the balance to zero, so the schedule never produces a negative ending balance. Extra principal can reduce later interest because future interest is calculated on a smaller balance. The model assumes no prepayment penalty, no new borrowing, no payment pause, and no capitalization event.
The interest and payoff comparisons are most useful as sensitivity analysis: change one assumption at a time and observe the effect on the total. A lower rate, shorter term, or larger extra payment generally reduces total interest, though a shorter term raises the scheduled monthly payment. Federal or private loan contracts may use daily simple interest, special allocation rules, fees, or repayment programs that make an actual statement differ slightly from this monthly model.