Student Loan Calculator
Estimate the monthly payment and total interest on a student loan.
Results update as you type.
About this calculator
A student loan calculator works out the fixed monthly repayment and total interest on a student loan from the balance, interest rate and repayment term. The standard repayment plan is a 10-year amortising schedule; a longer term lowers each payment but adds a lot of interest over the life of the loan.
It applies the usual amortisation formula, splitting each payment between interest on the remaining balance and principal. For example, a 30,000 balance at 5.5% over 10 years costs about 326 a month, with roughly 9,100 of total interest. An optional extra monthly payment goes straight to principal, shortening the term and cutting that interest.
Use it to plan repayments after graduation, to compare the standard 10-year plan with a longer term, or to see how much interest an extra payment saves. It models a single fixed-rate loan; income-driven plans, forgiveness programs and variable rates work differently and are not captured here.
Frequently asked questions
How is a student loan payment calculated?
It uses the standard amortisation formula on the balance, rate and term, giving an equal payment each month. A 30,000 balance at 5.5% over 10 years is roughly 326 a month.
Should I extend the term to lower payments?
Extending to 20 or 25 years reduces the monthly payment but can nearly double the interest you pay. If cash flow allows, a shorter term or extra payments save the most money.
How can I pay off student loans faster?
Add an extra amount to each payment or make one-off lump-sum payments toward principal — the extra-payment field shows the months and interest saved. Targeting the highest-rate loan first, or refinancing to a lower rate, also speeds payoff.
Should I refinance my student loans?
Refinancing to a lower rate cuts interest and can shorten the term, which this tool can illustrate by lowering the rate. But refinancing federal loans into a private loan gives up federal protections like income-driven repayment and forgiveness, so weigh that carefully.
How is interest calculated on a student loan?
Most student loans accrue interest daily on the outstanding balance and it is billed monthly. This calculator uses standard monthly amortisation, so early payments are mostly interest and later ones mostly principal.
What is the difference between subsidised and unsubsidised loans?
On subsidised loans the government pays the interest while you are in school and during grace periods, so the balance does not grow then. Unsubsidised loans accrue interest the whole time, which can capitalise onto the balance — enter the balance that reflects any accrued interest.
API — use this calculator from code
Call this calculator as a free JSON endpoint — no key required. Send the field values below as query parameters or JSON. Read the full API docs →
Endpoint
GET https://calculator.free/api/v1/student-loan/curl
curl "https://calculator.free/api/v1/student-loan/?balance=30000&rate=5.5&years=10"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/student-loan/?" + new URLSearchParams({
"balance": "30000",
"rate": "5.5",
"years": "10"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.