Student Loan Calculator
Work out your monthly payment, total interest, and what refinancing or an extra payment would actually save.
Your details
Details
Interest usually accrues during grace and deferment on unsubsidised loans
Refinancing
This calculator runs entirely on your device. Nothing you enter is uploaded, stored, or sold. How this works
Monthly payment
$432.06
Paid off in 10 yrs
Includes your inputs, the full breakdown, and every row of the table.
Total interest
$13,848
Total repaid
$51,848
Interest saved by extra
—
Time saved
—
- Original balance
- $38,000
- Balance at repayment
- $38,000
- Required payment
- $432.06
- Total monthly payment
- $432.06
- Interest over the loan
- $13,848
- Total repaid
- $51,848
- Refinanced at 5.00%
- $403.05/mo
- Interest if refinanced
- $10,366
| Month | Payment | Interest to date | Balance |
|---|---|---|---|
| 12 | $432.06 | $2,399.01 | $35,214.25 |
| 24 | $432.06 | $4,610.56 | $32,241.06 |
| 36 | $432.06 | $6,622.04 | $29,067.79 |
| 48 | $432.06 | $8,420.00 | $25,680.99 |
| 60 | $432.06 | $9,990.05 | $22,066.30 |
| 72 | $432.06 | $11,316.87 | $18,208.37 |
| 84 | $432.06 | $12,384.09 | $14,090.84 |
| 96 | $432.06 | $13,174.25 | $9,696.24 |
| 108 | $432.06 | $13,668.68 | $5,005.93 |
| 120 | $432.06 | $13,847.51 | $0.00 |
What this means
- Federal student loans carry protections that private loans do not — income-driven repayment, deferment, forbearance, and forgiveness programmes. Refinancing federal loans with a private lender permanently gives all of that up, even if the rate is lower.
- Interest on unsubsidised loans accrues during school and grace periods, and is usually capitalised into the balance when repayment begins.
- Student loan interest of up to $2,500 a year may be deductible depending on income, which lowers the effective rate slightly.
How the student loan calculation works
Student loan repayment looks like a mortgage in structure — a fixed payment amortised over a set term — but behaves differently in one important way: the borrower usually has options that other debt does not offer.
Before optimising for the lowest rate, work out whether your loans are federal or private. Federal loans come with income-driven repayment plans, forbearance if you lose your job, and potential forgiveness for public service. Refinancing them into a private loan is irreversible and forfeits every one of those protections.
For private loans, the calculation is simpler and refinancing is usually straightforward arithmetic. Compare the total interest at your current rate against the refinanced figure, and check for origination fees.
The extra payment line is where most of the leverage sits. Because student loans are typically simple-interest and have no prepayment penalty, every additional dollar reduces principal directly and compounds into a shorter term.
Frequently asked questions
Should I refinance my federal student loans?
Only if you are confident you will never need income-driven repayment, deferment, or forgiveness. Refinancing federal loans privately is permanent and cannot be undone.
Does paying extra reduce my monthly payment?
No — it shortens the term instead. Contact your servicer to make sure extra payments are applied to principal rather than advancing your due date.
What is capitalised interest?
Unpaid interest added to your principal balance, usually when repayment begins. From then on you pay interest on that interest, which is why the balance at repayment can exceed what you borrowed.
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Disclaimer. This calculator is provided for general information and educational purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Results are estimates based on the inputs you provide and the assumptions described above. Confirm any figure with a qualified professional before acting on it.