Student Loan Calculator
Project student loan repayments, including interest that accrues while studying.
Please note: An estimate, not a repayment schedule. Government student loans are often repaid as a percentage of income above a threshold, with interest, thresholds and any write-off set by rules that change — this projects a conventional loan and cannot model your scheme.
What the Student Loan Calculator does
Unsubsidised student loans accrue interest from the day they are disbursed, including while you study. That interest is usually capitalised — added to the principal — when repayment begins, so you then pay interest on interest.
Formula
Accrued interest = P × monthly rate × grace monthsPayment = (P + accrued) × r × (1+r)ⁿ ÷ ((1+r)ⁿ − 1)
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Total borrowed | selected currency | Yes | Accepts more than 0. |
| Annual interest rate | % | Yes | — |
| Repayment term | years | Yes | Accepts 0 or more, up to 50. |
| Months before repayment starts | number | Optional | Accepts 0 or more. |
| Interest during the grace period | one of 2 options | Yes | — |
| Currency | one of 10 options | Optional | — |
How to use it
- Choose Interest during the grace period and Currency.
- Enter Total borrowed, Annual interest rate and Repayment term.
- Optionally add Months before repayment starts.
- Select Calculate.
Worked example
$40,000 borrowed at 5.5%, 6-month grace, unsubsidised, repaid over 10 years.
- Borrowed
- 40000
- Rate
- 5.5
- Term
- 10
- Grace
- 6
- Interest
- Accrues
Balance grows to $41,100, monthly payment $446.05, total interest $14,426.
Frequently asked questions
What does capitalised interest mean?
Unpaid interest is added to your principal, so future interest is charged on the larger balance. Paying interest during study avoids it entirely.
Should I pay extra while studying?
If the loan is unsubsidised, even small payments that cover the accruing interest stop the balance from growing.
Method and sources
Method. Interest accrued during the grace period is calculated simply (principal × monthly rate × months) and, where capitalisation is selected, added to principal before the standard amortizing-loan formula is applied to the resulting balance.
Assumptions
- Capitalisation, when selected, is assumed to happen once, in full, at the end of the grace period — the common convention, though a specific loan servicer may apply it differently.
- The rate is treated as fixed for repayment; many government loan schemes instead set or adjust the rate by rule.
Limitations
- This models a conventional fixed-payment loan only. Income-driven repayment, subsidy during study, and forgiveness or discharge programmes are not represented at all — where your loan uses one, this figure will not match your actual schedule.
- No government rate table or threshold schedule is used; every figure comes from what you entered.