Student Loan Calculator

The calculator uses the standard amortization formula: payment = principal x (r x (1 + r)^n) / ((1 + r)^n - 1), where r is the monthly interest rate and n is the number of months in your term. The result is a fixed dollar amount that covers interest first each month and retires the full balance by the last payment. If your rate is 0%, the payment is simply the balance divided by the number of months.

On subsidized federal loans, the government covers the interest while you are in school, in deferment, or during the grace period, so your balance stays at the original amount when repayment starts. On unsubsidized and private loans, interest accrues the entire time and capitalizes into the principal at the end of the grace period, raising the balance you actually repay.

For unsubsidized loans, the calculator accrues simple interest for each month of the grace period (typically 6 months on federal loans) and adds it to your principal before computing your payment. For example, a $30,000 balance at 6.5% gains about $975 in capitalized interest over a 6-month grace period, so your effective starting balance is roughly $30,975. Subsidized loans skip this step entirely, so your balance stays unchanged.

Yes, if your budget allows. Federal and most private student loans carry no prepayment penalty, so every extra dollar goes directly to principal and cuts the interest that accrues the following month. The calculator shows you exactly how many months you save and how much interest you avoid. Adding even $50 to $100 per month to a 10-year loan can trim years off repayment and save thousands of dollars.

Federal student loans default to a 10-year Standard Repayment Plan (120 monthly payments). Extended plans can stretch to 25 years, and income-driven plans adjust your payment based on earnings. Longer terms lower your monthly payment but substantially increase total interest, so the calculator lets you compare terms side by side to see the real cost difference.