Browse all calculators →
Fixed and income-based repayment
Write-off modelling included
Month-by-month amortisation
Income scenarios compared
Estimate only
HomeCalculatorsDebt & LoansStudent Loan Calculator

Student Loan Calculator
Repayment, Interest & Payoff Timeline

Calculate your student loan repayment timeline, monthly payment, total interest, and whether your loan will be paid off or written off. Supports fixed monthly repayment and income-based repayment.

Country
Currency
🏫
Your Student Loan
Loan Details
Your current outstanding loan balance.
%
The annual interest rate applied to your loan.
Repayment Mode
Your fixed monthly repayment amount. Must exceed monthly interest to reduce the balance.
Your current gross annual income.
Annual income above which repayments apply.
%
Percentage of income above threshold deducted as repayment.
Write-Off & Term
yrs
Any remaining balance written off after this period. Select no write-off for standard loans.
%
Expected annual income growth rate. Used to project rising repayments in income-based mode.
🎉
Monthly Payment
per month
Total Repaid
cash out of pocket
Total Interest
interest accrued
Payoff / Write-Off
years from now
Loan Balance
starting
Interest Rate
annual
Monthly Interest
on opening balance
Monthly Payment
repayment
Monthly Principal
balance reduction
Total Repaid
all payments
Total Interest
over loan life
Amount Written Off
if applicable
Years to Payoff
or write-off
Interest / Repaid
interest share
Repayment Breakdown
Monthly payment
Years to clear
Total repaid
Total interest
Amount written off
Monthly payment
Years to clear
Total repaid
Total interest
Amount written off
Loan Balance Over Time
Balance
Cumulative repaid
Balance at Milestone Years
YearBalance RemainingCumulative RepaidCumulative InterestStatus
Important: This calculator estimates student loan repayment using the balance, interest rate, and repayment parameters you enter. It does not apply any country-specific loan plan rules, income-contingent repayment legislation, interest rate caps, government write-off policies, or repayment holiday provisions. Results are estimates only. Always check with your loan servicer or official student finance body for accurate figures.
✦ Cal, AI Explanation
Cal is reviewing your loan breakdown...
💬 Ask Cal about your student loan
Cal
Your student loan estimate is ready. Ask me about how interest builds up, whether income-based repayment makes sense, or what write-off means for your loan.

How student loan repayment works

Student loan repayment depends on whether your plan uses a fixed monthly payment or income-based repayment. Interest accrues on the outstanding balance every month. Each payment first covers that month's interest, with any remainder reducing the principal. If the payment is smaller than monthly interest, the balance grows.

Repayment TypeHow It WorksKey Variable
Fixed monthly paymentSame amount each month; balance reduces steadily if payment exceeds interestPayment amount
Income-based repaymentA percentage of income above a threshold; payment rises with earningsIncome, threshold, rate
Write-offRemaining balance cancelled after a fixed number of yearsWrite-off year

When balance grows despite making payments

If the monthly interest accruing on the loan is larger than the monthly payment, the unpaid interest is added to the balance. This is called negative amortisation. It is common with income-based plans when income is low and the repayment is below the interest cost. The balance will keep growing until income rises enough for repayments to exceed monthly interest.

Should you overpay a student loan with a write-off?

Whether overpaying makes financial sense depends on whether you expect to clear the loan before the write-off date. If your projected repayments under normal conditions would result in a write-off of a large balance, overpaying accelerates payoff but means you repay more than you would have needed to. If you expect to clear the loan well before write-off, overpaying saves interest. The comparison section in this calculator shows both scenarios side by side.

Income-based repayment and income growth

Income-based plans charge a percentage of earnings above a threshold. As income grows, the repayment amount grows and the loan reduces faster. This calculator projects income growth at an annual rate you enter, which increases the monthly payment each year and changes the payoff timeline accordingly.

Frequently Asked Questions

Why is my student loan balance increasing?+
If your monthly payment is less than the interest accruing on the balance that month, the difference is added to the principal. This happens frequently with income-based repayment plans when income is low, or at the start of repayment when balances are large relative to payments. The balance will start falling once repayments exceed monthly interest.
What is a repayment threshold?+
A repayment threshold is the annual income level above which student loan repayments are triggered. You only repay a percentage of the income that exceeds this threshold. If your income falls below the threshold, repayments stop automatically. The threshold is set by your loan plan and may change each year.
What does write-off mean for a student loan?+
A write-off means any remaining loan balance is cancelled by the lender or government after a fixed number of years of repayment. You are no longer required to repay the written-off amount. However, in some countries a written-off balance may be treated as taxable income in the year it is cancelled. The rules depend on your country and loan plan.
Is it worth making extra payments on a student loan?+
Extra payments reduce the balance and save interest, but they only make financial sense if you are likely to clear the loan before the write-off date. If the loan will be written off regardless, extra repayments mean you pay more than necessary. Use this calculator to compare the total amount repaid under normal and accelerated schedules before deciding.
Why does this calculator not show my exact plan details?+
Student loan rules are highly specific to each country, loan plan, and year of study. Thresholds, rates, interest caps, and write-off terms are updated regularly and differ between plans within the same country. This calculator uses the values you enter to give a planning estimate. For your exact figures, check with your official student loan servicer.