Estimate your student loan payment once repayment starts, including interest that builds up while you study, and see how extra payments shorten the loan.
How to use the student loan calculator
- Enter what you've borrowed (or will borrow), the interest rate and the repayment term. Ten years is a common fixed term; your lender or servicer shows yours.
- Enter the months until repayment starts, for example your remaining study time plus a grace period. Use 0 if you're repaying now.
- Choose what happens to interest until then: added to the balance, kept separate (US federal loans), paid by you each month, or none (subsidized).
- Read your monthly payment and payoff date, and try extra payments.
Example: $30,000 at 6.5%, 6 months before repayment, 10-year term
Simple interest builds at $30,000 × 6.5% ÷ 12 = $162.50 a month, $975.00 over 6 months. What you pay then depends on what happens to it:
| Interest before repayment | Monthly payment | Total interest |
|---|
| Added to the balance | $351.71 | $12,206 |
| Kept separate, paid off first | $351.53 | $12,184 |
| Paid each month while studying | $340.64 | $11,852 |
| None (subsidized) | $340.64 | $10,877 |
Total interest includes the interest from before repayment, whoever pays it. Stretching the same loan to 20 years lowers the payment to $230.65 but raises total interest to $25,356.
What this calculator does and doesn't do
It works out fixed payments that repay the loan by the end of the term: standard and extended plans, private student loans and education loans in India (where the time before repayment is called the moratorium and the payment is an EMI). It doesn't model income-driven repayment, which depends on your income and family size, or any loan forgiveness. Rates on variable-rate private loans change over time; this assumes the rate you enter stays fixed.
For UK Plan 1, 2, 4, 5 and postgraduate loans, the UK tax calculator shows the deduction from your pay. For other loans, try the loan calculator.
Frequently asked questions
How is a student loan payment calculated?
Like any fixed-payment loan: M = P × i ÷ (1 − (1 + i)^−n), with P what you owe when repayment starts, i the yearly rate ÷ 12 and n the number of months. $30,000 at 6.5% over 10 years is $340.64 a month if no interest built up before repayment.
Does interest build up while I'm in school?
On most loans, yes, as simple interest on what you borrowed: $30,000 at 6.5% builds $162.50 a month. On US Direct Subsidized Loans you don't pay the interest while you're enrolled at least half-time or during the 6-month grace period. Choose the option that matches your loan under "Interest until then".
What does capitalized interest mean?
It's unpaid interest added to your balance, so you then pay interest on it too. After 6 months, $975 added to $30,000 makes the payment $351.71 instead of $340.64. US federal Direct Loans stopped capitalizing interest when you first start repaying on 1 July 2023; the unpaid interest stays separate and your payments clear it first ($351.53 a month in this example). Many private lenders still capitalize it.
Should I pay the interest while I'm still studying?
It costs $162.50 a month in the example, but keeps your balance at $30,000, so the payment after school is $340.64 and total interest is $11,852, against $12,206 if the interest is added to the balance.
Can I pay off a student loan early?
US federal Direct Loans can be prepaid at any time without a penalty; check a private loan's agreement. Adding $100 a month to the 10-year example clears it 2 years 10 months sooner and saves $3,373 in interest.
Does this work for UK student loans?
Not really. UK student loans are repaid as a share of your income above a threshold, not as a fixed monthly payment, so the amount depends on what you earn. The UK tax calculator works out the yearly student loan deduction from your salary.