Student Loan Calculator
Work out your monthly student loan payment, total interest, and payoff date — and see how much faster you finish (and how much interest you save) by adding an extra payment each month.
How to Use
- Enter your total loan balance — the amount you still owe across the loans you want to model together.
- Set the APR (annual percentage rate). Federal and private student loans typically run from about 4% to 8%.
- Choose the term in years — the standard federal repayment plan is 10 years.
- Add any extra monthly payment you can make on top of the required amount to attack the principal faster.
- Read the monthly payment, total interest, payoff time, and the interest you save by paying extra.
Show Work
Notes
About the Student Loan Calculator
Working on personal-finance and money decisions? The Student Loan Calculator is a free browser tool that gives you the answer in seconds. Work out your monthly student loan payment, total interest, and payoff date — and see how much faster you finish (and how much interest you save) by adding an extra payment each month.
How it works
Put each value in its box and read the answer as you go. Because it recalculates live, you can play with the inputs to see how each one moves the result — handy for checking your own working or planning ahead. Everything happens on your device, so it is fast and private.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
How is my student loan monthly payment calculated?
It uses the standard amortization formula: payment = P·r / (1 − (1+r)⁻ⁿ), where P is the balance, r is the monthly rate (APR ÷ 12), and n is the number of months. Early payments are mostly interest; later payments are mostly principal. This tool shows the full breakdown in the Show Work section.
Does paying extra each month really help?
Yes — every extra dollar goes straight to principal, which shrinks the balance that future interest is charged on. Even a modest extra payment can knock years off the term and save thousands in interest. Try the "aggressive" preset to see the effect of $300 extra per month.
What APR should I use?
Use the rate from your loan servicer. Federal undergraduate loans are often in the 4–6% range; graduate and private loans can be higher. If you have several loans at different rates, you can model them separately, or use a weighted-average rate as an approximation.
Is this for federal or private loans?
Both — the math is the same for any fixed-rate, fully-amortizing loan. It does not model income-driven repayment, deferment, subsidized-interest periods, or loan forgiveness, which change the picture for some federal borrowers.
Why is my total interest so high?
Interest is charged on the outstanding balance every month, so a long term means you pay interest for longer. Stretching a loan to lower the monthly payment increases total interest. Shortening the term or adding extra payments is the most direct way to cut the total cost.
How do I use the Student Loan Calculator?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Do I need to install or sign up for anything?
Not at all — it runs in the browser with nothing to install and no account. After it loads once, it even works without an internet connection.
Is my information private?
Yes. Everything happens in your browser. Nothing you type is sent to a server or saved anywhere.
Common Use Cases
Planning a repayment budget
See the required monthly payment before you commit, so it fits your budget.
Testing extra payments
Find out how many months and how many dollars an extra payment each month saves you.
Comparing loan terms
Weigh a shorter term with higher payments against a longer, cheaper-per-month one.
Refinance decisions
Estimate the new payment and total interest at a lower refinanced rate.
Payoff goal setting
Target a payoff date and back out the extra payment needed to hit it.
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