Fixed-rate student loan repayment: how it works
A fixed-rate student loan amortizes like any other loan: equal monthly payments over the agreed term, with each payment split between interest on the outstanding balance and principal reduction. Early payments go mostly to interest; later payments mostly reduce what you owe.
On a $30,000 loan at 6.5% for 10 years, your monthly payment is approximately $341 and total interest paid is roughly $10,900 — about 36% of the original loan amount. A shorter term raises the monthly payment but substantially reduces total interest.
This calculator is pre-filled with typical private student loan figures. Update the fields to match your actual loan. If you have multiple loans, run the calculator separately for each — or use the combined balance if they share the same rate and term.
Paying off student loans faster: the numbers
Extra payments on student loans work exactly the same as any other amortizing loan — each extra dollar eliminates the interest it would have generated for all remaining periods. The benefit is largest early in the loan when the outstanding balance is highest.
Use the Payoff Accelerator mode to enter an extra monthly amount (say, $100 or $200) and see how many months it cuts from your term and how much total interest it saves. A lump sum — a tax refund, a bonus, or a gift — can have a similarly large effect applied at the right time.
If you have both subsidized and unsubsidized federal loans, directing extra payments to the highest-rate loan first minimizes total interest (the avalanche method). Run each loan separately in the calculator to compare the impact.
Income-driven repayment: what this calculator does not cover
Income-driven repayment (IDR) plans calculate your payment as a fixed percentage of your discretionary income — not as a standard amortization on your balance. In the US, the SAVE, PAYE, IBR, and ICR plans each use different income thresholds, cap payments differently, and have different forgiveness timelines. In the UK, Plan 1, Plan 2, Plan 4, and Plan 5 threshold and write-off rules change annually. In Australia, HECS-HELP repayments are indexed to CPI and income, not to loan balance.
These plans cannot be modeled with a standard amortization formula, and the rules change frequently enough that any static calculator risks giving outdated guidance. For IDR planning, use the official government tools:
Frequently asked questions
How do I calculate my student loan monthly payment?
For a fixed-rate student loan, the same amortization formula applies: M = P × [r(1+r)^n] / [(1+r)^n − 1]. On a $30,000 loan at 6.5% for 10 years (120 months), the monthly payment is approximately $341 and total interest paid is roughly $10,900. Enter your actual loan amount, rate, and term in the calculator above to get your exact figures.
Does this calculator work for federal student loans?
This calculator is designed for fixed-rate, fully-amortizing loans — including fixed-rate federal direct loans and private student loans. It does NOT model income-driven repayment plans (SAVE, PAYE, IBR, ICR in the US; Plan 1, Plan 2, or Plan 5 in the UK; HECS/HELP indexation in Australia). Those plans calculate payments as a percentage of your income, not on a standard amortization schedule, and the rules change regularly. Use this calculator for standard fixed-rate repayment; cross-links to income-driven calculators are at the bottom of this page.
How much do extra payments save on student loans?
Extra payments reduce your principal faster, which lowers the interest charged on all future periods. On a $30,000 loan at 6.5% for 10 years, adding $100/month extra reduces the payoff time by approximately 2 years and saves roughly $2,500 in interest (computed approximately; use the Payoff Accelerator mode for your exact numbers). The savings are front-loaded: extra payments in the first few years save more than the same payments later.
Should I refinance my student loans?
Refinancing federal student loans into a private loan permanently gives up federal protections: income-driven repayment, deferment, forbearance, and forgiveness programs. If you have federal loans and might need those protections, refinancing is a significant trade-off to weigh carefully. For private student loans, refinancing to a lower rate is generally straightforward — use the Refinance Comparison mode to find your break-even month for any rate and term change.
What is the standard repayment plan for federal student loans?
The US standard repayment plan sets a fixed monthly payment over 10 years (120 months) designed to pay off your balance in full. It produces the lowest total interest of all federal repayment options, though the monthly payment is higher than income-driven alternatives. Enter your loan balance and your interest rate (listed on studentaid.gov) into the calculator above to see the exact payment this plan would require.