Daily Interest Calculator

Can you save on interest by making loan payments sooner?


Generally, interest on student loans is calculated daily. The daily interest is the amount of interest that you would normally be required to pay each month on your loan. Use this calculator to:

  • Figure out the interest amount owed since your last payment.
  • Experiment with the "number of days" field to see how making payments earlier results in a lower interest amount.
Loan Principal (Balance Owed) $
Number of days since last payment
Annual Interest Rate %
Interest Rate Factor
Interest Amount $

What is the loan principal balanced owed?  Loan principal balance owed is the original amount(s) disbursed for the loan(s), any adjustments made to the loan disbursement amount, and any capitalized interest added to the loan account.

What is the annual interest rate?  A rate which is charged or paid for the use of money. An interest rate is often expressed as an annual percentage of the principal.

What is the Interest Rate Factor? This number is an intermediate number used to calculate a daily rate. It is determined by taking the annual rate and dividing it by the number of mathematical days in an average year (365.25).

What does this mean? The number of days between your last payment, the interest rate, and your loan balance determines the amount of interest that accrues each month.

Example Scenario: You still owe $8,600 on your student loan. Twenty-eight days after your previous month's payment, you make a payment of $150. Your interest rate is 8.5% (.085), which when divided by 365.25 results in an interest rate factor of .00023272.

28 (Days since last payment) x $8,600 (Balance Owed) x .00023272 (Interest rate factor) = $56.04 (Interest)

Of your $150 payment, $56.04 goes toward interest and $93.96 goes toward the principal balance. Therefore, your new loan balance is now $8,506.04 after your $150.00 payment is applied.


Note: This calculator is provided for estimation purposes only. If you are seeking specific details about individual loan payments, repayment schedules, alternative payment plans, and other repayment options, contact your lender/servicer for more information.


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