Free Student Loan Calculator
Enter your loan balance, interest rate, and repayment term to see your monthly payment, the total interest you will pay, and the month your loan is gone.
This free student loan calculator amortizes your balance at your interest rate over your chosen term. For example, $30,000 at 6 percent over 10 years costs about $333 a month, with about $9,967 in total interest and a payoff date 10 years out. Shorter terms and extra payments cut the interest dramatically.
Estimates only for standard repayment. Income-driven plans, forgiveness programs, and variable rates change the picture. Federal loans have protections private loans lack. Not financial advice.
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How student loan math works
Student loans amortize like any installment debt: each payment covers that month's interest first, and the rest reduces principal. The monthly payment comes from the amortization formula with your balance, monthly rate, and number of payments. On $30,000 at 6 percent over 120 payments, the math gives about $333 a month.
Early payments are interest-heavy. In month one of that loan, about $150 of the $333 is interest and only $183 touches principal. That ratio improves every month as the balance shrinks, which is why the loan feels slow at first and then accelerates.
The term dominates total cost. Stretch $30,000 at 6 percent to 20 years and the payment falls to about $215, but total interest jumps from about $9,967 to about $21,579. You buy a $118 smaller payment with $11,600 of extra interest. Income-driven plans stretch even further, with even larger lifetime interest.
Extra payments attack principal directly and skip future interest. Adding $100 a month to that 10-year loan pays it off about 2.5 years early and saves roughly $2,700 in interest. There is no prepayment penalty on federal loans or most private ones, so extra payments are pure win when you have no higher-rate debt.
Interest capitalization is the trap to watch. On unsubsidized federal loans, interest accrues while you are in school and capitalizes, gets added to principal, at repayment. A $30,000 loan can easily be $35,000 by graduation. Paying interest during school, even small amounts, prevents the balance from growing before you start.
Student loan questions
How is a student loan payment calculated?
The standard repayment formula: balance times the monthly interest rate, divided by one minus (1 + monthly rate) raised to the negative number of payments. For $30,000 at 6 percent over 120 monthly payments, that is about $333 a month.
How much interest will I pay on my student loans?
Total interest is driven by the three inputs together. At 6 percent, $30,000 costs about $9,967 in interest over 10 years but about $21,579 over 20 years. Higher rates scale it further: at 8 percent over 10 years, interest reaches about $13,500.
Should I pay off student loans early?
Compare the loan rate to your alternatives. Above 6 or 7 percent, extra payments are a strong move, a guaranteed return at that rate. Below 4 or 5 percent, investing the extra money often wins over decades. Always keep an emergency fund and capture any employer retirement match before accelerating low-rate loans.
What is the difference between subsidized and unsubsidized loans?
On subsidized federal loans, the government covers interest during school, grace periods, and deferment, so the balance does not grow. On unsubsidized loans, interest accrues from disbursement and is added to the principal when repayment begins, meaning you pay interest on interest.