Student Loan Calculator
Plan student loan repayment, see total interest under different plans and compare standard, graduated and income-driven repayment options.
How to use the Student Loan Calculator
- Enter your inputs into the Student Loan Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The standard student loan payment
M = P · r(1 + r)^n / ((1 + r)^n − 1)
Same fixed-payment amortization formula as any installment loan. Federal Direct loans use a 10-year standard term by default; refinancing can extend or shorten it.
Worked example
$45,000 in federal direct loans at 6.5% over 10 years: M ≈ $511/month, total interest ≈ $16,300. Extending to 20 years reduces the payment to $335/month but more than doubles interest to about $35,400.
Frequently asked questions
Should I refinance federal loans?
Refinancing into a private loan can lower the rate but you lose access to income-driven repayment, public service forgiveness and forbearance protections. The savings have to be worth giving up those options.
What is income-driven repayment?
IDR plans cap payment at 5–20% of discretionary income with forgiveness after 20–25 years. Useful for borrowers with high debt-to-income or pursuing PSLF.
Does paying extra help with student loans?
Yes — federal loans have no prepayment penalty. Specify that extra payments go to principal on the highest-rate loan; otherwise some servicers credit them to future payments instead.