Student Loan Calculator
See what your student loans will cost each month and in total, and how much faster you could clear them with a higher payment.
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Understanding student loan repayment
Student loans are amortising loans like any other: fixed payment, fixed rate, interest charged on the outstanding balance. What makes them different is the range of repayment plans available and the fact that the balance is often large relative to the income of the person repaying it. The standard federal plan runs for ten years, and extended plans stretch to 25, which lowers the monthly payment but substantially increases what you pay in total.
The arithmetic is unforgiving at longer terms. Borrowing 40,000 dollars at 5.5 percent over the standard ten years costs 434.11 dollars a month and 12,093 dollars in interest. Stretching to 25 years would reduce the monthly figure but raise the total interest considerably. That trade-off matters most for borrowers whose income is expected to rise, because paying more early while earning less is harder than paying more later.
Interest accrues from the day the loan is disbursed, including while you are still studying if the loan is unsubsidised. This is why the amount you repay is often noticeably larger than the amount you thought you borrowed. Capitalised interest, where unpaid interest is added to the principal at the end of a deferment or forbearance period, compounds the effect and is worth avoiding where possible.
If you are struggling with the required payment, income-driven repayment plans cap it at a percentage of your discretionary income and forgive the remaining balance after a set number of years. Whether that is better than paying aggressively depends on your income trajectory and the tax treatment of any forgiven amount, which is a question for a tax professional rather than a calculator. This tool models fixed-rate repayment so you can see the baseline cost of the debt itself.
How the payment is calculated
The same amortisation formula used for any fixed-rate instalment loan.
| Symbol | Meaning |
|---|---|
A |
Monthly payment |
P |
Amount borrowed |
i |
Monthly interest rate: annual rate divided by 12 |
n |
Total number of monthly payments |
This models a fixed-rate loan in full repayment. It does not include income-driven repayment caps, subsidised interest during study, deferment or forgiveness, all of which change the total cost and depend on your individual circumstances.
Worked example: 40,000 dollars over 10 years
A 40,000 dollar balance at 5.5 percent repaid over the standard ten-year term.
| Figure | Result |
|---|---|
| Amount borrowed | $40,000.00 |
| Monthly payment | $434.11 |
| Interest paid in month 1 | $183.33 |
| Principal repaid in month 1 | $250.77 |
| Total interest over 10 years | $12,092.61 |
| Total repaid | $52,092.61 |
| Number of payments | 120 |
You repay 52,093 dollars for 40,000 dollars of borrowing, so the debt costs about 30 percent more than the amount advanced. In month one, 42 percent of the payment is interest. Adding 100 dollars a month to the payment would clear the balance roughly a year and a half early and save several thousand dollars in interest.
Estimates only. Your lender's figures may differ because of fees, escrow and rounding.
Paying student loans down efficiently
Know which loans cost you most
If you have a mixture of federal and private loans, list them by interest rate and target the highest first while paying the minimum on the rest. This is the avalanche method and it minimises total interest mathematically.
Stop interest capitalising
During deferment or forbearance, unpaid interest is added to the principal and then itself attracts interest. If you can pay even the interest while not required to make payments, you avoid that compounding entirely.
Check whether you qualify for forgiveness
Public Service Loan Forgiveness and various income-driven forgiveness programs can eliminate a remaining balance after a qualifying period. If you might qualify, overpaying a loan that would otherwise be forgiven is money wasted. Check eligibility before choosing a strategy.
Direct extra money to the highest rate
A 7 percent graduate loan costs more per dollar than a 4 percent undergraduate loan. The same extra payment saves more when aimed at the higher rate, even though the balance on the other loan may be larger.
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Frequently asked questions
What is the standard student loan repayment term?
Ten years for the standard federal plan, which is the term that produces the lowest total interest. Extended plans stretch to 20 or 25 years and reduce the monthly payment, but you pay interest for far longer and therefore considerably more overall.
Should I pay extra on my student loans?
It depends on the rate and on whether forgiveness is likely. If your rate is above what you could earn safely elsewhere and you are not pursuing forgiveness, extra payments give a guaranteed return equal to the rate. If a forgiveness program will clear the balance, overpaying reduces the amount forgiven.
How does interest accrue while I am studying?
On unsubsidised loans interest begins accruing immediately, including during study and any grace period. If it is not paid as it accrues it is capitalised into the principal, which means you then pay interest on the interest. Subsidised loans have the government pay the interest during qualifying periods.
Are student loan interest rates fixed or variable?
Federal student loans have fixed rates set annually by statute. Private student loans may be fixed or variable, and variable-rate loans can rise substantially over a long repayment term. Check which you have before assuming the payment is stable.
Does refinancing student loans make sense?
Refinancing with a private lender can lower the rate, but it converts federal loans into private ones and permanently gives up federal protections such as income-driven repayment, deferment options and forgiveness eligibility. For many borrowers that trade is not worth the rate reduction.