How to use this calculator
- Add each student loan with its current balance and interest rate. You can list up to 10 loans.
- The calculator combines them into one weighted average interest rate, based on how much of your total balance each loan makes up.
- Choose a repayment plan: Standard (10 years), Extended (25 years, shown once your combined balance is over $30,000), or a custom term you set yourself.
- Add an optional extra monthly payment to see how much sooner you'd be done and how much interest it saves.
- Compare every plan's payment, total interest, and payoff date in the table, and review the balance chart before exporting or sharing your scenario.
How it's calculated
Each loan is amortized separately, at its own rate, over the plan's term: M = L × r(1 + r)n ÷ [(1 + r)n − 1] for each loan, where n is the plan's term in months. That matches how a real Standard, Extended, or custom repayment plan schedules multiple loans — each loan keeps its own rate — rather than blending every loan's balance and rate into one payment, which understates both the payment and the total interest whenever your loans' rates differ (a $20,000 loan at 3% plus a $20,000 loan at 12% pays about $480/mo combined, not the roughly $475/mo a single blended-rate loan at the weighted average would suggest).
The weighted average interest rate shown — Σ(balance × rate) ÷ Σ(balance) — mirrors the single number federal loan servicers quote for a repayment plan, but here it's an informational figure only; it isn't used to calculate your payment or interest.
Extra monthly payments are applied avalanche-style: they go to whichever remaining loan has the highest rate, and once a loan is fully paid off, its own payment amount is redirected to the next-highest-rate loan still outstanding — the total amount you pay each month stays the same, but more of it goes to principal on your most expensive debt.
Standard Repayment spreads your balance over 10 years (up to 30 for Direct Consolidation Loans, not modeled separately here) with a fixed payment. Extended Repayment stretches federal Direct Loans over up to 25 years, lowering the monthly payment but increasing total interest, and is only available once you owe more than $30,000 in Direct Loans.
This calculator does not model income-driven repayment (IDR) plans — including Income-Based Repayment (IBR) and the new Repayment Assistance Plan (RAP) — because eligibility, payment formulas, and even which plans exist have changed multiple times since 2024 and remain subject to further litigation and rulemaking. Check studentaid.gov's current IDR plans for up-to-date rules and to run an official estimate with the Loan Simulator.
Calculations keep full precision month to month and round only the numbers you see. Every schedule is capped so an unrealistic payment (too small to cover interest) can't create an endless loop — the calculator will show that the loan never pays off instead.
Assumptions
- All loans are treated as fixed-rate for the life of the plan; federal Direct Loans are fixed by law, but older FFEL or variable-rate private loans can change.
- Extended Repayment eligibility here is based only on your combined balance (over $30,000); actual eligibility depends on your loan type and servicer, and private loans don't offer it at all.
- Interest accrues monthly on the combined balance from your entered start month; grace periods, deferment, forbearance, and capitalized interest before that date aren't modeled.
- Income-driven repayment, Public Service Loan Forgiveness, and other forgiveness programs are not modeled — see studentaid.gov for those calculations.
- Results are estimates for planning only. Confirm your actual servicer-assigned rate, plan options, and payment with your loan servicer or at studentaid.gov.
Frequently asked questions
How is the weighted average interest rate calculated?
Each loan's balance is multiplied by its rate, those are added up, and the total is divided by your combined balance: Σ(balance × rate) ÷ Σ(balance). A $20,000 loan at 5% and a $10,000 loan at 7% gives a weighted average of (20,000×5% + 10,000×7%) ÷ 30,000 = 5.67%. Larger balances pull the average toward their own rate. This figure is shown for reference only — your payment and total interest are calculated by amortizing each loan separately at its own rate, not at this blended rate.
What's the difference between Standard and Extended repayment?
Standard Repayment pays off your federal loans in up to 10 years with a fixed payment. Extended Repayment stretches Direct Loans over up to 25 years, which lowers your monthly payment but increases total interest, and it's only offered to borrowers with more than $30,000 in outstanding Direct Loan debt.
Why don't I see the Extended repayment option?
Extended Repayment requires more than $30,000 in combined Direct Loan debt. Add your loan balances above — once their total passes $30,000, the Extended (25-year) plan appears as an option.
What are income-driven repayment plans, and why doesn't this calculator include them?
Income-driven repayment (IDR) plans set your payment as a share of your discretionary income instead of a fixed schedule. The specific plans, formulas, and even names have changed repeatedly in recent years — the SAVE plan was struck down in court, PAYE is closing to new enrollment, and a new Repayment Assistance Plan (RAP) launched in 2026 — so we point you to studentaid.gov/idr for a current, official IDR estimate rather than model rules that may already be out of date.
Does paying extra each month actually help with student loans?
Yes. Extra payments go straight to principal, which lowers every future month's interest charge and shortens the loan. Confirm with your servicer that extra payments are applied to principal (and, if you have multiple loans, to the one you intend) rather than held toward next month's bill.
Should I pick the shortest term or the lowest payment?
A shorter term (like Standard's 10 years) means a higher monthly payment but far less total interest. A longer term (like Extended's 25 years) lowers the monthly payment but costs more overall. If your budget allows it, a shorter term or extra payments on a longer term usually save the most money; if cash flow is tight, a longer term keeps payments manageable while you get on your feet.
Can I use this calculator for private student loans?
Yes, for the payoff math — enter the balance and rate and it will amortize like any fixed-rate loan. Just note that Extended Repayment, weighted-average grouping by a servicer, and federal protections like IDR or forgiveness generally don't apply to private loans.
How many loans can I add?
Up to 10 loans at once. If you have more, group loans with the same rate together, or add your largest loans individually and combine the rest into one row using their own weighted average balance and rate.
Does this calculator affect my actual loan or servicer account?
No. It's an independent estimate for planning purposes only. Nothing you enter here is sent to your loan servicer, and changing your actual repayment plan requires a request through your servicer or studentaid.gov.
Why is my servicer's weighted average rate slightly different from this calculator's?
Servicers typically round the weighted average to the nearest whole or 1/8 percentage point, and may calculate it separately for each loan type (subsidized vs. unsubsidized, or by loan program) rather than across everything at once. This calculator uses the unrounded, all-loans-combined average for a closer look at the true blended cost.
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Disclaimer: This calculator provides estimates for educational purposes only and is not financial, tax, or legal advice or an offer of credit. Actual payments depend on your lender, loan terms, taxes, and insurance. Consult a qualified professional before making financial decisions.