This student loan calculator turns a loan balance into a plan: the standard monthly payment, the total interest you will pay over the term, and what paying extra each month does to both.
Federal borrowers: income-driven plans, forgiveness programs and deferments change real-world outcomes and are outside this standard-plan math — check your servicer’s figures for those paths. Consolidating multiple loans? Enter the combined balance and the balance-weighted rate.
The Standard Plan, and the Cost of Time
Student loans amortize like any other installment debt — the payment formula is identical — but two features are unique to them: interest that may have been capitalizing (added to principal) during school and grace periods, so the balance entering repayment is often larger than what was borrowed; and a menu of federal repayment plans (standard 10-year, extended, income-driven, forgiveness tracks) that trade payment size against total cost in ways this calculator’s extra-payment field lets you sanity-check. Juggling these with other debts? The Debt Payoff Calculator compares attack orders. Part of our Finance Calculators collection.
Worked Example (Verified)
$30,000 at 5.5% on the standard 10-year plan:
- Monthly payment: $325.58 · Total repaid: $39,069 · Total interest: $9,069 — you hand back nearly a third again of what you borrowed
- Add $100/month extra: the loan dies in about 7 years 2 months instead of 10, and interest falls to about $6,300 — roughly $2,750 saved (run your own balance through the widget for your exact figures)
- The first payment’s split is instructive: $137.50 of it is interest — early payments mostly rent the money; extra payments attack principal directly, which is why they punch above their size
Decisions Worth Modeling Here First
- Refinancing (private): each 1% rate cut on $30k/10y saves roughly $1,800 of interest — but refinancing federal loans surrenders federal protections (income-driven plans, forgiveness eligibility, deferments). Price the protections before trading them.
- Extended 25-year terms halve the payment and roughly triple total interest on typical balances — a cash-flow tool, not a savings tool.
- Paying during school on unsubsidized loans: the interest-only payments feel small because they are — and they prevent the capitalization that silently inflates the starting balance.
Related Tools
- Debt Payoff Calculator — multiple debts, one plan
- Personal Loan Calculator — the same math, general purpose
- Finance Calculators — the full collection
Frequently Asked Questions
What is the monthly payment on a $30,000 student loan?
At 5.5% over 10 years: $325.58. The same balance at 7% pays $348.33; over 20 years the payment drops to about $206 but total interest roughly doubles — term and rate both matter, in that combination.
How much interest will I pay on my student loans?
On the standard plan, roughly 30% of the borrowed amount at typical federal rates (the example’s $9,069 on $30,000). Income-driven plans can pay substantially more in interest even as balances are eventually forgiven.
Does paying extra on student loans help?
Yes — extra payments apply to principal, shortening the loan and cutting total interest (about $2,750 saved and nearly 3 years freed by +$100/month on the example). There are no prepayment penalties on federal or standard private student loans.
What is interest capitalization?
When unpaid interest is added to your principal — after school, grace or deferment periods — so future interest accrues on a larger base. It is why balances can enter repayment higher than the amount originally disbursed.
Should I refinance my student loans?
If you hold federal loans, refinancing into a private loan trades away income-driven repayment and forgiveness options for a lower rate. It suits borrowers with stable high income and no forgiveness path — model the interest saving here, then weigh what you’d give up.
Is this student loan calculator free?
Yes — free, instant, no sign-up.