Student Loan Calculator: Deferred Interest and Repayment

How deferred student-loan interest is estimated

The calculator uses simple monthly interest before repayment. When interest is capitalized, it is added once to the original principal when repayment begins. When interest is paid during deferment, the balance remains unchanged. The subsidized scenario assumes no borrower interest accrues during the entered period.

Repayment payment and total interest

After deferment, the calculator amortizes the repayment balance with equal monthly principal-and-interest payments. Total projected interest combines borrower-paid interest before repayment with interest charged during repayment. A subsidized period contributes no borrower interest under this scenario.

Origination fee and net disbursement

The entered origination fee is deducted from the amount disbursed but does not reduce the loan principal. A $30,000 loan with a 1% fee provides $29,700 of net proceeds while the starting principal remains $30,000.

Example

A $30,000 loan at 6% that accrues interest for four years plus a six-month grace period accumulates about $8,100 before repayment. If capitalized, approximately $38,100 is amortized. Paying the monthly interest during school avoids that capitalization under the calculator’s assumptions.

Important limits

This is a general planning tool, not a federal or private loan-program calculator. It does not model income-driven repayment, forgiveness, consolidation rules, daily interest, changing rates, capitalization events during repayment, taxes, servicer rounding, borrower benefits, or current government program rules. Confirm the exact balance, subsidy status, fee and repayment options with the lender or servicer.

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