Student Loan Interest Calculator
See how much interest your student loans cost and how it accrues over time.
Student loan interest accrues daily: your balance times the rate, divided by 365. On a $30,000 loan at 6% that is about $4.93 a day, or roughly $148 in the first month. Over a standard 10-year term you pay close to $9,967 in total interest. Enter your balance, rate, and term to see total interest and how it shrinks as the balance falls.
These results are estimates for informational purposes only and are not financial, tax, or legal advice. Your actual figures from a lender or the IRS may differ. Consult a qualified professional before making decisions.
Estimated monthly payment
$333.06
Principal vs. interest paid per year
Amortization schedule
| Year | Principal | Interest | Balance |
|---|---|---|---|
| 1 | $2,258 | $1,739 | $27,742 |
| 2 | $2,397 | $1,599 | $25,344 |
| 3 | $2,545 | $1,451 | $22,799 |
| 4 | $2,702 | $1,294 | $20,097 |
| 5 | $2,869 | $1,128 | $17,228 |
| 6 | $3,046 | $951 | $14,182 |
| 7 | $3,234 | $763 | $10,948 |
| 8 | $3,433 | $563 | $7,515 |
| 9 | $3,645 | $352 | $3,870 |
| 10 | $3,870 | $127 | $0 |
About the Student Loan Interest Calculator
Most student loans use simple daily interest, which means interest is calculated on your outstanding balance every day rather than once a month. The daily amount equals your balance multiplied by the annual rate and divided by 365, and those daily charges add up to the interest portion of each monthly payment. This calculator shows the total interest across the life of the loan and how the interest share of each payment falls as the balance drops. Early payments are mostly interest; later ones are mostly principal. One trap to watch is capitalization, when unpaid interest is added to your principal, after a deferment or at the end of a grace period on an unsubsidized loan. Once that happens you start paying interest on the interest, which quietly raises your cost. Paying even small amounts during school or making payments on the first of the month rather than the due date reduces the interest that accrues, since the balance the daily formula runs against is lower.
Frequently asked questions
How is student loan interest calculated?+
Federal and most private loans use a simple daily formula. Multiply your current balance by the interest rate, divide by 365, and that is the interest added each day. The month's daily charges become the interest part of your payment.
What is interest capitalization?+
Capitalization is when unpaid interest is added to your principal balance, usually after a grace period, deferment, or forbearance. From then on interest is charged on the larger balance, so you end up paying interest on interest.
Does paying early reduce student loan interest?+
Yes. Because interest accrues daily on the balance, paying before the due date or making extra payments lowers the balance the daily formula uses, so less interest builds. Ask your servicer to apply extra amounts to principal.
Can I deduct student loan interest?+
You can deduct up to $2,500 of student loan interest a year as an above-the-line deduction, even if you do not itemize, subject to income limits set by the IRS. Your servicer reports the amount you paid on Form 1098-E.