Student Loan Calculator

Student loan debt is one of the largest financial obligations most people take on early in life. In the United States alone, outstanding student loan debt exceeds $1.7 trillion, with the average borrower owing around $37,000. Understanding the true cost of your loan -- not just the amount you borrowed, but the total interest you will pay over the life of the loan -- is essential for financial planning. This calculator breaks down every aspect of your student loan repayment so you can make informed decisions.

The calculator uses standard amortization math. Each monthly payment is divided between principal (reducing what you owe) and interest (the cost of borrowing). Early in the loan term, a larger portion of each payment goes toward interest. As you pay down the principal, the interest portion shrinks and more of each payment chips away at the balance. This is why extra payments early in the loan have the greatest impact on total interest paid.

The formula for calculating monthly payments on a fixed-rate loan is M = P * [r(1+r)^n] / [(1+r)^n - 1], where P is the principal (loan amount), r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments (years times 12). This formula ensures that every payment is the same amount and that the loan is fully paid off by the end of the term.

The optional extra payment feature shows you exactly how much you can save by paying more than the minimum each month. Even small additional amounts can dramatically reduce your total interest and shorten your payoff timeline. For example, adding just $50 per month to a $30,000 loan at 5.5% over 10 years can save over $1,500 in interest and pay off the loan more than a year early. The calculator shows the exact savings in dollars and months.

The amortization table displays a month-by-month breakdown of each payment, showing how much goes to principal versus interest and the remaining balance after each payment. The first 12 months are shown by default, with an option to expand the full table. The payment breakdown pie chart provides a visual summary of the total principal versus total interest over the life of the loan, making it immediately clear how much borrowing actually costs you.

Use the interest rate slider to compare different loan offers, or adjust the term length to see how shorter repayment periods reduce total interest at the cost of higher monthly payments. These trade-offs are the foundation of smart student loan management, and this tool makes them visible and concrete.

Monthly payment is calculated using the standard fixed-rate amortization formula: M = P * [r(1+r)^n] / [(1+r)^n - 1]. Interest is compounded monthly. The amortization schedule iterates month by month, applying interest to the remaining balance, then subtracting the payment. Extra payments are applied directly to principal reduction. All calculations run entirely in your browser -- no financial data is stored or transmitted.