About the Student Loan Calculator
A student loan often grows before you have to pay anything back. Interest can build up while you are studying and during a grace period, and if you don't pay it, it is added to the loan, so you then pay interest on the interest. This student loan calculator takes the amount you borrow, the interest rate, the months before repayment starts and the length of repayment, and shows the interest that builds up, the balance when repayment begins, the monthly payment, and the total interest over the loan. You can compare letting the interest add up with paying it as you go, to see how much that choice saves.
Updated October 2026
How to use the Student Loan Calculator
- 1Enter the total amount you borrow and the interest rate.
- 2Enter the months before repayment starts, such as the years of study plus any grace period.
- 3Choose whether to let interest add to the loan or pay it each month while you study.
- 4Enter the repayment period in years.
- 5Read the monthly payment, the balance at the start of repayment and the total interest.
A worked example
Borrow 30,000 at 6.5 percent with 54 months before repayment. If you let the interest add up, it grows by about 8,775 and you start repaying 38,775 over 10 years, at roughly 440 a month, paying about 22,800 in interest in total. If you pay the roughly 162 a month of interest while studying, you start repayment with 30,000, pay about 341 a month for ten years and spend about 10,900 on interest after study, plus the interest paid during study.
Ways to reduce the cost
- Borrow only what you need, and check scholarships and grants first
- Pay interest during study if you can
- Choose a shorter repayment period when you can afford it
- Make extra payments, targeted at the highest-rate loan
- Ask about rate discounts for automatic payments
Related tools
The College Cost Calculator estimates future costs and savings, the Loan Calculator and Amortization Calculator show a schedule, the Debt Payoff Calculator helps plan extra payments, the Interest Rate Calculator finds an unknown rate and the Salary Calculator turns pay into monthly figures. This tool gives estimates and is not financial advice.
Features
- Interest that builds up while you study
- Interest added to the loan or paid early
- Balance at the start of repayment
- Monthly payment for any repayment period
- Total repaid and total interest
- Monthly interest cost during study
- Runs in your browser
Frequently asked questions
How is student loan interest calculated?
Interest builds up each month at one twelfth of the yearly rate on the balance. A 30,000 loan at 6.5 percent accrues about 162 a month. Over four and a half years of study and grace, that is roughly 8,800 if it isn't paid, which is added to the balance when repayment begins.
What is capitalised interest?
It is unpaid interest that is added to the loan balance, so that future interest is charged on a larger amount. It makes the loan grow even before you start repaying. Paying the interest while you study stops this and lowers the total cost.
Should I pay interest while I'm still in school?
If you can afford to, it usually saves money, because the balance never grows. The calculator shows the payment and total cost both ways. Even partial payments help. If your loan is subsidised and the government pays the interest while you study, you don't need to.
What repayment period should I choose?
A shorter period means higher payments but much less interest overall. A longer one lowers the payment but costs more in total. Choose the shortest period your budget can comfortably manage, and make extra payments when you can if there is no penalty.
Does the calculator cover several loans?
It treats your borrowing as a single loan. For several loans with different rates, either calculate each separately and add the payments, or enter the total with an average rate weighted by balance. Income-driven repayment plans also work differently and aren't covered here.
Does the tool include fees or forgiveness?
No. Origination fees, rate discounts for automatic payments and forgiveness programmes are not included. Check the terms of your loan and any programmes you might qualify for.