Student Loan Calculator
Your monthly student loan payment, the interest, and how much paying extra saves.
Good to know. An extra 50 a month on a student loan is a pay rise nobody taxes: it earns exactly the loan’s interest rate.
Not financial advice. Uses only the numbers and rates you enter — no live data.
How it works
In plain words
A student loan on a fixed plan is repaid like any other loan: the same payment each month, covering that month’s interest and part of the balance. Paying extra goes straight to the balance, so less interest builds up afterwards.
The formula
payment = balance × r ÷ (1 − (1 + r)^−n), r = rate ÷ 12, n = months interest = payment × n − balance
Worked example
30,000 at 6.5% over 10 years is 340.64 a month, with 10,877 of interest. Paying 100 more each month clears it in 7 years 2 months and saves about 3,350 of interest.
Sources
- Brealey, Myers and Allen, Principles of Corporate Finance, chapter 2 The standard formulas for loan payments, compounding and present value, the same as a spreadsheet’s PMT and FV.
- Federal Student Aid, Interest rates and fees for federal student loans Rates for Direct loans by academic year.
- GOV.UK, Repaying your student loan UK thresholds, the 9% rate and write-off terms.
Sources checked September 30, 2026. 3 automated tests check its answers on every change.
About the student loan calculator
This calculator works out the monthly payment on a student loan with a fixed rate and a fixed repayment plan, such as the 10-year standard plan for US federal loans or a private student loan. It also shows how much quicker the loan is cleared, and how much interest you save, by paying a little extra each month.
A longer plan lowers the monthly payment but costs much more in interest: the same 30,000 at 6.5% costs about 10,900 in interest over 10 years and over 23,700 over 20. If you can afford the standard plan, it is usually the cheapest. If you pay extra, ask your servicer to apply it to the principal of the highest-rate loan, not to next month’s payment.
US federal loans also have income-driven repayment plans, where the payment depends on your income and family size instead of the balance, and any balance left after 20 to 25 years may be forgiven. Those plans have changed several times recently; studentaid.gov shows the options for your loans.
UK student loans work differently: you repay 9% of your income above a threshold (6% for postgraduate loans), whatever the balance, and anything left is written off after 25 to 40 years depending on the plan. Many graduates never repay in full, so paying extra often makes little sense there.
Questions people ask
How much is the payment on a 30,000 student loan?
About 341 a month at 6.5% over 10 years, or about 224 over 20 years, which costs much more interest.
Should I pay off student loans early?
Paying extra saves interest at the loan’s rate. It usually makes sense after building an emergency fund and paying off higher-rate debt, and if your loan isn’t heading for forgiveness.
How do UK student loan repayments work?
You repay 9% of income above your plan’s threshold, taken from your pay. The balance doesn’t change the payment, and what is left is written off after the plan’s term.