Student Loan Calculator
Estimate your monthly payment and the total cost of repayment.
- Author
- CentCompass Research Team
- Reviewed by
- Editorial Review
- Last Updated
- Reading Time
- 4 min read
Monthly payment
$397.42
Total interest
$12,690.15
Total repaid
$47,690.15
Months to payoff
120
| Year | Balance | Interest paid to date |
|---|---|---|
| 1 | $32,430.33 | $2,199.34 |
| 2 | $29,688.56 | $4,226.59 |
| 3 | $26,763.17 | $6,070.21 |
| 4 | $23,641.86 | $7,717.92 |
| 5 | $20,311.51 | $9,156.58 |
| 6 | $16,758.12 | $10,372.21 |
| 7 | $12,966.75 | $11,349.85 |
| 8 | $8,921.47 | $12,073.59 |
| 9 | $4,605.27 | $12,526.40 |
| 10 | $0.00 | $12,690.15 |
What is the Student Loan Calculator?
A student loan calculator estimates the monthly payment on an education loan and shows what the debt costs in total once interest is included. It also models what happens when you pay more than the required amount — usually the single most effective lever a borrower controls, because student loans often run for a decade or more and interest compounds over that whole period.
How the calculation works
The balance is amortized over the repayment term at your interest rate, producing a level monthly payment that clears the debt exactly at the end. Each month, interest is charged on what remains and the rest of the payment reduces the principal, so the split shifts steadily toward principal as the balance falls. Any extra payment you add bypasses interest entirely and goes straight to principal, which shrinks every future interest charge — the reason a modest extra amount early can remove years from the loan.
The formula
The standard payment follows M = P · [r(1+r)^n] / [(1+r)^n − 1], where P is the balance, r the monthly rate (annual rate ÷ 12), and n the number of months. Total interest is M × n − P. With an extra payment E, each month reduces the balance by (M − interest + E) instead, so the schedule ends early; the interest saved is the difference between the two totals. Note this models the standard plan — income-driven plans recalculate the payment from income instead.
Worked example
A $35,000 balance at 6.5% on a standard 10-year plan carries a payment near $397 and costs roughly $12,690 in interest across the full term. Adding $200 a month changes the picture substantially: the loan clears in 71 months — just under six years instead of ten — and saves about $5,471 in interest. The extra money does nothing but reduce principal, and every dollar of principal removed early stops accruing interest for the entire remaining term.
Tips
- Confirm your servicer applies extra payments to principal rather than advancing your due date.
- Target the highest-rate loan first when you hold several, since that is where interest accrues fastest.
- Check eligibility for federal forgiveness or income-driven plans before aggressively prepaying.
- Federal student loans carry no prepayment penalty, so paying ahead is always allowed.
- Interest that accrues during deferment may capitalise, raising the balance the payment is based on.
Common mistakes
- Prepaying private loans while ignoring higher-rate credit card debt.
- Sending extra money without instructing the servicer to apply it to principal.
- Refinancing federal loans privately and permanently losing forgiveness and income-driven options.
- Assuming the standard plan is the only option when income-driven plans may fit better.
- Forgetting that unpaid interest can capitalise after deferment, enlarging the principal.
Limitations
This models a fixed-rate loan on a standard level-payment plan. It does not cover income-driven repayment, graduated or extended plans, forgiveness programs, deferment and forbearance, interest capitalisation, loan consolidation, or the variable rates found on some private loans. Borrowers with federal loans should check the official repayment options before deciding on a strategy.
Frequently asked questions
How is my student loan payment calculated?
On a standard plan the payment is the level amount that fully repays principal and interest across the term. It depends only on the balance, the interest rate, and the number of months — change any one and the payment moves.
What is the difference between federal and private student loans?
Federal loans come with fixed rates set by law, access to income-driven repayment, deferment options, and potential forgiveness. Private loans are underwritten on credit, may carry variable rates, and generally offer none of those protections.
Should I pay extra on my student loans?
If you hold private loans or federal loans you do not expect to have forgiven, extra payments reduce total interest meaningfully. If you are pursuing forgiveness through an income-driven plan, prepaying can actually reduce the amount eventually forgiven.
What is income-driven repayment?
Income-driven plans set the payment as a share of discretionary income rather than from the balance, and can forgive the remainder after a qualifying period. Payments can be far lower than the standard plan, though more interest accrues over a longer term.
What is interest capitalisation?
Capitalisation adds unpaid accrued interest to the principal, typically after a deferment or a change of repayment plan. Because future interest is then charged on the larger balance, it makes the loan more expensive.
Should I refinance my student loans?
Refinancing can lower the rate on private loans. Refinancing federal loans into a private one permanently forfeits income-driven repayment, deferment protections, and any forgiveness eligibility — a trade that is rarely worth a modest rate cut.
Is there a penalty for paying off early?
Federal student loans never carry a prepayment penalty, and it is uncommon on private loans, though it is worth confirming in the agreement. Paying early reduces total interest because interest accrues on the outstanding balance.
Which loan should I target first when I have several?
Mathematically, the highest interest rate first minimises total cost. Some borrowers prefer clearing the smallest balance first for momentum; both work, but the rate-first approach is the cheaper of the two.
What happens if I miss payments?
Federal loans become delinquent and eventually default, which damages credit and can trigger wage garnishment or tax refund offset. Contacting the servicer early usually opens options such as a different plan or temporary forbearance.
Is student loan interest tax deductible?
There is a federal deduction for student loan interest subject to income limits and an annual cap, available even without itemising. Whether you qualify depends on your income and filing status, so check the current rules.
Related calculators
Related guides
Sources
- Federal Student Aid (ED) — Repayment Plans
- CFPB — Student loans
How this page is produced and reviewed
Editorial process. Content is written by the CentCompass Research Team, then checked against the official publications listed above by Editorial Review before it goes live. This page was last reviewed on . See our editorial policy.
How the calculations work. Every result comes from a small, unit-tested calculation engine rather than a spreadsheet or a hardcoded table. Loans use the standard amortization formula, growth uses compound-interest math, income tax applies the federal progressive brackets, and payroll applies Social Security and Medicare rules. Our methodology sets out each one.
Where the figures come from. Tax brackets, standard deductions, FICA parameters, and contribution limits are stored once in a dated registry and read directly by the calculators — the same values appear in the text above, so the two can never drift apart. Each figure records its source, effective tax year, and review status on our data sources page.
Update policy. Regulatory figures are reviewed when the IRS, SSA, or another authority publishes new values — typically each autumn for the following tax year — and again at the scheduled review date recorded for each dataset. Figures awaiting a second reviewer are marked as draft on the data sources page until that check is complete.
Educational purposes only — not financial, tax, or investment advice (disclaimer).