Student Loan Payment Calculator
A fixed-rate loan payment is set by three numbers: the balance, the interest rate and the length of the term. Enter those below and the calculator returns the monthly payment, the total you will repay across the whole term, and how much of that total is interest.
That third figure is the one worth looking at hardest. Two loans with the same monthly payment can differ by thousands in what they eventually cost, and the difference is almost always the term.
Calculate your monthly payment
Enter the annual interest rate, not the monthly one. The rate on federal loans is fixed for the life of the loan.
What the payment is actually made of
Every payment is split between interest and principal. Interest is charged on whatever balance remains, so at the start — when the balance is at its largest — most of the payment goes to interest and only a little touches what you owe. As the balance falls, the interest portion shrinks and the principal portion grows. The payment stays the same; its composition changes every month.
This is why the early years of a loan feel like standing still, and why an extra payment made early is worth far more than the same payment made late. It also explains the shape of the total: lengthening the term reduces the monthly figure but adds years of interest on a balance that is coming down more slowly.
The calculator assumes a fixed rate and equal payments. Variable-rate private loans move with an index, so treat the result as a snapshot rather than a schedule.
The trade-off between the payment and the total
Stretching a term is the usual response to an unaffordable payment, and it works — but the cost is not obvious from the monthly figure alone. The table holds the balance and rate constant and varies only the term, so every difference is caused by time.
| Term | Effect on monthly payment | Effect on total interest |
|---|---|---|
| 10 years | Highest | Lowest |
| 15 years | Lower | Higher |
| 20 years | Lower still | Higher still |
| 25 years | Lowest of these | Highest of these |
Run your own numbers in the calculator rather than trusting a rule of thumb — the size of the gap depends heavily on the rate.
Federal and private loans behave differently
Federal student loans carry a fixed rate set for the year in which they are disbursed, and that rate stays with the loan for its life. Deliberately, this page quotes no rate: these are static pages, a figure written into the prose would be wrong within a year, and the current one is published at studentaid.gov. Put the rate from your own loan into the calculator instead.
Federal loans also come with repayment options that change the calculation entirely — income-driven plans set the payment from your income rather than from the balance, so the standard amortisation this tool performs will not describe them. Use it for the standard plan, for a private loan, or to see what a fixed payment would look like against an income-driven one.
Private loans are ordinary consumer credit: the rate depends on credit and may be variable, and the protections are narrower. If you are comparing a refinance offer against federal loans, the interest saving is only one side of the comparison — refinancing federal debt privately gives up income-driven repayment and the federal forgiveness routes permanently.
Reading the total repaid honestly
The total the calculator reports assumes every payment is made on schedule and nothing changes. Real repayment rarely runs that cleanly, and several ordinary events move the number.
- Interest that accrues before repayment begins. Unsubsidised loans accrue during study and any grace period, and unpaid interest can be added to the balance — after which you pay interest on it.
- Deferment or forbearance. Pausing payments does not usually pause interest, so a pause lengthens the term and raises the total.
- Extra payments, which do the reverse and often by more than expected — see the payoff calculator for what they are worth.
- A refinance, which replaces the loan entirely with a new rate and term, making the original total irrelevant.
- Multiple loans. Most borrowers hold several with different rates and balances; run each separately rather than averaging them, because the highest-rate loan behaves very differently from the lowest.
What to do with the answer
The monthly figure tells you whether the loan fits your budget. The total tells you what the loan costs. Those are two different questions and they often point in opposite directions, which is precisely why both are shown.
A practical order: check the monthly payment against income first, because a payment you cannot make leads to delinquency and that is worse than any interest figure. Then look at the total, and treat any room between the payment you can afford and the payment required as the space for extra principal. Small, consistent amounts applied early are the highest-return use of that room.
Frequently asked questions
From the balance, the monthly interest rate and the number of months in the term, using the standard amortisation formula. The payment stays fixed while its split between interest and principal shifts — interest-heavy at the start, principal-heavy at the end.
It lowers the monthly payment and raises the total. You are borrowing the same money for longer, so more interest accrues. Use the calculator to see the size of the gap for your own rate before choosing a term on the monthly figure alone.
The one on your own loan. Federal rates are fixed for the life of the loan and set by disbursement year, and the current figures are published at studentaid.gov. This page deliberately quotes no rate, because a number written into a static page would be stale within a year.
No. Income-driven plans set the payment from your income and family size rather than from the balance and term, so standard amortisation does not describe them. Use this for the standard plan or a private loan, or to compare what a fixed payment would look like.
Because interest is charged on the outstanding balance, which is at its largest at the start, so most of each early payment covers interest. The principal share grows every month as the balance falls — which is also why an extra payment made early is worth much more than the same payment made late.