Student Loan Calculator: Monthly Payment & Total Interest
Work out the monthly payment and total interest on a student loan, and see how much faster a shorter term clears the balance.
Adjust the inputs and select Calculate for a full breakdown.
Year-by-year amortization schedule
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Monthly payment | Total interest | Total of payments |
|---|---|---|---|
| $30k · 6.5% · 10-year | $340.64 | $10,877.27 | $40,877.27 |
| $50k · 7.0% · 15-year | $449.41 | $30,894.54 | $80,894.54 |
| $15k · 5.5% · 10-year | $162.79 | $4,534.73 | $19,534.73 |
| $80k · 8.0% · 20-year | $669.15 | $80,596.49 | $160,596.49 |
How This Calculator Works
Enter your student loan balance, its interest rate, and the repayment term. The standard repayment plan amortizes the loan over ten years, but extended and graduated plans run longer. The calculator produces one constant monthly payment and shows how the balance and the interest share of each payment change across the term.
The Formula
Fixed-Rate Amortization
P = loan amount, r = monthly rate (APR ÷ 12), n = number of monthly payments
Worked Example
A $30,000 student loan at 6.5% over the standard 10-year term costs about $341 a month. By the time the balance clears you have repaid roughly $40,900, so interest adds close to $10,900 to what you originally borrowed.
Key Insight
Extending the term lowers the monthly payment but raises total interest sharply, because the balance is exposed to interest for longer. Any extra payment applied to principal shortens the loan and cuts interest more than the amount itself.
Frequently Asked Questions
What repayment term should I use?
The federal standard plan is ten years. Extended plans can run to 25 years with lower monthly payments but much higher total interest. Enter the term that matches your repayment plan.
Does this cover federal and private loans?
Yes. The amortization math is the same for both. Use the actual rate and term from your loan servicer, since federal and private loans are priced differently.
How does interest capitalization affect my loan?
When unpaid interest is added to the principal — capitalized — future interest is charged on the larger balance. Enter the balance after any capitalization for an accurate result.
Should I pay more than the minimum?
Extra payments applied to principal reduce the balance faster and cut total interest. Confirm with your servicer that overpayments go to principal rather than to future installments.
What about income-driven repayment?
Income-driven plans set the payment from your income rather than the balance, so this fixed-amortization calculator does not model them. Use it for standard, extended, or private loan repayment.
Related Calculators
Data Sources & Benchmarks
This calculator draws on 3 independent, dated sources.
Methodology & Review
Payments use the standard fixed-rate amortization formula on a single fixed rate. The calculator does not model income-driven plans, deferment, or interest subsidies; results are checked against servicer disclosures.
Written by Ugo Candido · Last updated May 17, 2026.