Student Loan Calculator: Monthly Payment & Total Interest
Work out the monthly payment and total interest on a student loan, and see how much faster a shorter term clears the balance.
Adjust the inputs and select Calculate for a full breakdown.
Year-by-year amortization schedule
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Monthly payment | Total interest | Total of payments |
|---|---|---|---|
| $30k · 6.5% · 10-year | $340.64 | $10,877.27 | $40,877.27 |
| $50k · 7.0% · 15-year | $449.41 | $30,894.54 | $80,894.54 |
| $15k · 5.5% · 10-year | $162.79 | $4,534.73 | $19,534.73 |
| $80k · 8.0% · 20-year | $669.15 | $80,596.49 | $160,596.49 |
How This Calculator Works
Enter your student loan balance, its interest rate, and the repayment term. The standard repayment plan amortizes the loan over ten years, but extended and graduated plans run longer. The calculator produces one constant monthly payment and shows how the balance and the interest share of each payment change across the term.
The Formula
Fixed-Rate Amortization
P = loan amount, r = monthly rate (APR ÷ 12), n = number of monthly payments
Worked Example
A $30,000 student loan at 6.5% over the standard 10-year term costs about $341 a month. By the time the balance clears you have repaid roughly $40,900, so interest adds close to $10,900 to what you originally borrowed.
Key Insight
Extending the term lowers the monthly payment but raises total interest sharply, because the balance is exposed to interest for longer. Any extra payment applied to principal shortens the loan and cuts interest more than the amount itself.
Federal vs private student loans: different worlds
Federal student loans (Direct Subsidized, Unsubsidized, PLUS, Perkins) come with borrower protections that private loans don't have. Income-Driven Repayment plans (SAVE, IBR, PAYE) cap payments at 5-10% of discretionary income. Loan forgiveness after 20-25 years of qualifying payments (or 10 years under PSLF for public service workers). Deferment and forbearance during economic hardship. Death/disability discharge.
Private student loans (Sallie Mae, Discover, Citizens Bank, SoFi refinances): higher rates typically (especially for borrowers without strong credit history), no income-driven repayment, no forgiveness, no robust deferment. Standard 5-20 year fixed terms with monthly payments. Co-signer often required for undergraduates.
Strategic rule: NEVER refinance federal student loans to private unless you have strong stable income, no plans for public service work (PSLF eligibility), and the rate reduction is substantial (1.5%+). Refinancing eliminates federal protections permanently — a one-way door. The interest savings can be wiped out by losing income-driven repayment access during one downturn.
Income-Driven Repayment (IDR) options 2026: SAVE, IBR, PAYE
Federal IDR plans cap payments at a percentage of discretionary income (income above 150% of poverty line for family size). SAVE (Saving on a Valuable Education): undergraduate loans capped at 5% of discretionary income; graduate loans at 10%. Most generous current plan. PAYE: 10% of discretionary, 20-year forgiveness. IBR: 10-15% depending on when loans originated, 20-25 year forgiveness.
Worked example: graduate earning $60,000 with $50,000 in federal student loans. Standard 10-year payment plan: ~$525/month. SAVE plan with single filer: discretionary income = $60k − $22,590 (150% poverty single) = $37,410. Payment = 10% × $37,410 / 12 = $312/month. Saves $213/month immediately, with forgiveness of remaining balance after 20 years.
Tax bomb caveat: forgiven balances under IDR (not PSLF) are TAXABLE as ordinary income in the year of forgiveness. After 20 years of low payments, the remaining $60-100k forgiven could trigger $20-30k tax bill — a 'tax bomb'. Plan ahead: save for it OR target PSLF if eligible (tax-free forgiveness). For most middle-income borrowers, IDR + tax planning is still better than standard plan over loan life.
PSLF: Public Service Loan Forgiveness — the 10-year escape
Public Service Loan Forgiveness forgives REMAINING federal Direct Loan balance after 120 qualifying monthly payments (10 years) while working full-time for a qualifying employer: government (federal, state, local, tribal), 501(c)(3) nonprofit, military, AmeriCorps. The forgiveness is TAX-FREE — not the 'tax bomb' of IDR.
Strategic implication: PSLF is the most generous forgiveness program in US student loan history. For teachers, social workers, government employees, nonprofit workers, military officers earning $50-90k with $100-200k+ of federal loans — PSLF can forgive $80,000-150,000+ tax-free. Required: 120 payments under IDR while at qualifying employer.
Common PSLF mistakes: (1) Federal Family Education Loan (FFEL) Program loans don't qualify directly — must consolidate to Direct Loans first (resets payment count). (2) Not certifying employment annually via Employment Certification Form. (3) Switching to non-qualifying employer mid-stretch (payments stop counting). (4) Paying off loans early thinking 'it's better to just be done' — for PSLF-eligible borrowers, minimum IDR payments for 10 years then forgiveness is mathematically far better than aggressive payoff.
Federal student loan interest rates 2026 by loan type
Federal rates set annually by Congress based on 10-year Treasury note auction in May. 2026-27 rates apply to loans disbursed July 1, 2026 — June 30, 2027.
| Loan type | Interest rate | Borrowing cap (annual / aggregate) |
|---|---|---|
| Direct Subsidized (undergrad) | 6.39% | $3,500-$5,500/yr / $23,000 aggregate |
| Direct Unsubsidized (undergrad) | 6.39% | Combined with sub limits |
| Direct Unsubsidized (graduate) | 7.94% | $20,500/yr / $138,500 aggregate |
| Direct PLUS (grad/parent) | 8.94% | Cost of attendance minus other aid |
Federal rates change July 1 each year. Private student loan rates vary widely 4-15% APR depending on credit/cosigner. Federal rates are fixed for the life of each loan disbursement. Subsidized loans don't accrue interest while in school or deferment.
Frequently Asked Questions
What repayment term should I use?
The federal standard plan is ten years. Extended plans can run to 25 years with lower monthly payments but much higher total interest. Enter the term that matches your repayment plan.
Does this cover federal and private loans?
Yes. The amortization math is the same for both. Use the actual rate and term from your loan servicer, since federal and private loans are priced differently.
How does interest capitalization affect my loan?
When unpaid interest is added to the principal — capitalized — future interest is charged on the larger balance. Enter the balance after any capitalization for an accurate result.
Should I pay more than the minimum?
Extra payments applied to principal reduce the balance faster and cut total interest. Confirm with your servicer that overpayments go to principal rather than to future installments.
What about income-driven repayment?
Income-driven plans set the payment from your income rather than the balance, so this fixed-amortization calculator does not model them. Use it for standard, extended, or private loan repayment.
References & Authoritative Sources
- Federal Student Aid (StudentAid.gov) — Federal student loan programs and repayment plans · consulted May 31, 2026 · US Department of Education — official student loan portal, repayment plans, PSLF
- Department of Education — PSLF Help Tool — Public Service Loan Forgiveness eligibility · consulted May 31, 2026 · Official PSLF eligibility checker, employment certification, qualifying employer database
- Higher Education Act — Title IV — Statutory basis for federal student loan programs · consulted May 31, 2026 · Federal statute — Direct Loan program, IDR plans, PSLF authorization
Related Calculators
Data Sources & Benchmarks
This calculator draws on 3 independent, dated sources.
Methodology & Review
Payments use the standard fixed-rate amortization formula on a single fixed rate. The calculator does not model income-driven plans, deferment, or interest subsidies; results are checked against servicer disclosures.
Updated