About StudLoanCalc
StudLoanCalc is a free, privacy-first student loan calculator built to help the 45 million Americans with federal student loan debt make informed repayment decisions. Every calculation runs entirely in your browser — no data is ever collected, stored, or shared.
Why We Built This
In 2026, the U.S. student loan landscape underwent its most significant transformation in decades. The SAVE plan was terminated, the new RAP (Replacing SAVE) plan was introduced, and millions of borrowers needed clear, accurate tools to understand their options. Existing calculators required email signups, uploaded data to third-party servers, or hadn't been updated for the new rules. We built StudLoanCalc to fill that gap: a completely private, always-up-to-date calculator that puts you in control.
Methodology
All calculations in StudLoanCalc follow the formulas and parameters published by the U.S. Department of Education and are based on the 2026 Federal Student Aid regulations.
Amortization Engine
Standard loan amortization uses the standard PMT formula: M = P × [r(1+r)^n] / [(1+r)^n − 1] where P is principal, r is the monthly interest rate, and n is the total number of payments. For extra payment scenarios, the additional amount is applied to principal each month, reducing total interest and shortening the payoff period.
IDR Payment Calculation
Most Income-Driven Repayment (IDR) plans set the monthly payment as a percentage of discretionary income — Adjusted Gross Income (AGI) minus a multiple of the federal poverty guideline for the borrower's household size and state. RAP is the exception: it uses a percentage of your full AGI across 11 brackets.
- RAP: 1%–10% of your full AGI across 11 brackets (minus $50/month per dependent, $10/month minimum); 30-year forgiveness
- IBR: 15% of discretionary income above 150% of poverty guideline
- PAYE: 10% of discretionary income above 150% of poverty guideline, capped at Standard 10-year amount
For long-term projections, income is grown annually by the user-specified growth rate, and payments are recalculated each year.
PSLF Estimation
The PSLF estimator calculates projected monthly payments (based on the selected IDR plan), tracks the remaining qualifying payments toward 120, and projects the forgiven balance. The tool explicitly does not verify employer eligibility, determine whether past payments qualify, or adjudicate TEPSLF eligibility — these are determined exclusively by MOHELA.
Refinance Analysis
The refinance calculator compares the total remaining cost of the current federal loan against the cost of a new private loan with a different rate and term. Breakeven analysis accounts for any origination fees. The tool surfaces the complete list of federal protections that are permanently lost upon refinancing.
Debt Payoff Strategies
The Avalanche method targets the loan with the highest interest rate first, mathematically minimizing total interest. The Snowball method targets the loan with the smallest balance first, providing psychological motivation through quick wins. Both strategies apply minimum payments to all loans and direct the remaining budget (plus any extra) to the target loan.
Data Sources
- Federal Poverty Guidelines: U.S. Department of Health & Human Services (2026)
- Interest Rates: Federal Student Aid, 2025–2026 academic year rates per the Higher Education Act
- Repayment Plan Formulas: U.S. Department of Education, 34 CFR §682, §685
- PSLF Rules: studentaid.gov/pslf, MOHELA servicing guidelines
- Tax Deduction Limits: IRS Publication 970, IRC §221
- Teacher Loan Forgiveness: 34 CFR §685.217
See our References page for complete citations with links to official sources.
Author & Review
StudLoanCalc was developed by a financial education specialist with expertise in consumer debt analysis and federal student aid policy. Content and calculation formulas are reviewed against current U.S. Department of Education regulations and guidance published on studentaid.gov.
Our methodology prioritizes transparency: all formulas are documented on this page, and all policy parameters are extracted into a single configuration file that can be updated if federal regulations change — without altering the core calculation logic.
Our Commitment
- 100% Private: No accounts, no email collection, no data uploads. Your loan information stays on your device.
- Always Free: No paywalls, no premium features. We support the site through advertising.
- Transparent: All formulas and data sources are documented. No black-box calculations.
- Current: Based on 2026 federal regulations, with policy parameters structured for efficient updates if rules change.
Editorial Standards & Review Process
Because student loan decisions carry real financial consequences, we treat content accuracy as a core product feature rather than an afterthought. Every formula, plan parameter, and blog article is written from primary federal sources (the U.S. Department of Education, the Code of Federal Regulations, IRS publications, and HHS poverty guidelines) rather than from secondary news summaries.
How content is produced
- Source-first drafting: Calculations and explanations begin from the controlling statute or regulation, not from a third-party blog or forum post.
- Separate policy data: All plan percentages, poverty-guideline multipliers, and rate assumptions live in a single configuration file, so a value can be corrected in one place without touching calculation logic.
- Plain-language review: After a draft is written, it is read for clarity and checked against the original source to confirm no parameter was drifted or rounded in a misleading way.
- Disclosure of estimates: Where a number is illustrative (for example, a sample amortization), it is labeled as an example and is not presented as a quote for any specific borrower.
Update cadence
- Policy parameters: Reviewed whenever the Department of Education publishes a new rule or rate announcement. Major changes (such as the 2026 transition from SAVE to RAP) trigger a prompt update.
- Interest rates: Federal loan rates are set annually by Congress; we refresh them each academic year using the published Federal Student Aid rates.
- Poverty guidelines: HHS publishes new guidelines early each calendar year; IDR calculations use the guideline year matching the tax year being modeled.
- Page review date: Each content page carries a "Last Reviewed" date in the footer so you can see how fresh the material is.
How to Verify Any Number Yourself
We encourage every borrower to confirm important figures against official sources before acting. Building this habit also helps you spot errors anywhere on the web, not just on our site. A reliable cross-check takes about five minutes:
- Open the official Loan Simulator. Sign in at studentaid.gov/loan-simulator with your FSA ID. It uses your real loan balances and the current rules.
- Compare the monthly payment. Enter the same loan amount, rate, and term you used here and confirm the payment is within a few dollars. Small differences usually come from rounding or from capitalized interest on your real loan.
- Confirm the plan rules. For IDR plans, check the discretionary-income percentage and poverty multiplier directly on the ED repayment-plan pages linked from our References list.
- Verify forgiveness timelines. For PSLF, use the official PSLF Help Tool to certify employment; only MOHELA's count is authoritative for forgiveness.
If our calculator and the official tool disagree in a way you cannot explain, trust the official tool and tell us so we can investigate. A calculator is only as good as the inputs and the assumptions behind it.
Calculator Transparency: Worked Examples
The following examples show exactly how each tool arrives at its result. All figures are illustrative and use round numbers so the math is easy to follow; your real loan will differ.
Amortization example
A $30,000 loan at a 6.81% fixed rate over 10 years (120 months) uses the standard PMT formula. The monthly rate is 0.0681 ÷ 12 = 0.005675. Plugging in gives a payment of about $345 per month. Over 120 payments the borrower pays roughly $41,400 in total, meaning about $11,400 is interest. Adding $100 extra each month to principal shortens the term and cuts the interest substantially — the calculator shows the exact new payoff date.
IDR example (IBR vs PAYE)
Imagine a single borrower with $55,000 AGI and no dependents. Using the 2025 HHS poverty guideline for a one-person household in the contiguous 48 states ($15,650 — always confirm the current year's figure at aspe.hhs.gov), discretionary income under the standard definition is $55,000 − (1.5 × $15,650) = $31,525. Under IBR (15%), the monthly payment is 15% × $31,525 ÷ 12 ≈ $394. Under PAYE (10%), it is 10% × $31,525 ÷ 12 ≈ $263. The calculator applies the correct percentage and multiplier for whichever plan you select.
PSLF example
Continuing the PAYE example above, a borrower paying $263 per month for 120 qualifying months would pay about $31,560 toward the loan. If a large balance remains after 120 payments, that remaining balance is the amount projected for forgiveness. The calculator shows the projected forgiven balance but explicitly does not certify that your employer or payments qualify — only MOHELA makes that determination.
Refinance example
A borrower with the $30,000 federal loan above (6.81%, ~$345/month) might be offered a private refinance at 4.50% over 10 years, about $312 per month — roughly $33/month lower. The calculator quantifies that saving but also surfaces the trade-off: refinancing a federal loan permanently forfeits IDR access, PSLF eligibility, deferment/forbearance, and discharge protections. The lower payment is only worthwhile if those protections have no value to you.
Privacy & Data Handling in Detail
Privacy is not a footnote here; it is the reason the site is built the way it is. The entire calculation engine runs in JavaScript inside your own browser.
- No accounts: There is no sign-up, no login, and no profile. We have nothing to link your data to.
- No uploads: Your loan amounts, income, and balances never leave your device. They are not sent to any server.
- No tracking pixels for loan data: We use standard privacy-respecting analytics only to count page views in aggregate; we do not key analytics to individual loan inputs.
- Local storage only: If you save a loan log or scenario, it is stored in your browser's local storage on your device and can be cleared at any time.
- No data sales: We do not sell, rent, or share personal information with lenders, lead generators, or advertisers.
Funding Model & Editorial Independence
The site is supported by contextual advertising, which lets us keep every calculator free to use. Independence is protected by clear boundaries:
- No lender affiliate links: We do not earn commissions by steering you to any specific refinance company. Refinance results show the math, not a "apply now" payout.
- No lead generation: We do not collect your contact details to sell to lenders or brokers.
- Editorial separation: Advertisers have no influence over plan parameters, formulas, or the warnings we display about losing federal protections.
- Transparency: Advertising is clearly distinguishable from our own content and is never presented as a recommendation.
Known Limitations
- Estimates, not quotes: Outputs are projections based on the inputs and assumptions you provide, not binding figures from a servicer.
- Tax outcomes are simplified: The tax-bomb and deduction illustrations use general rules and do not model your full return; consult a tax professional for your situation.
- No eligibility adjudication: We cannot confirm PSLF employer eligibility, IDR recertification status, or forgiveness qualification.
- Capitalized interest: Real loans may include interest capitalized from prior deferment or forbearance that changes the starting balance.
- State law varies: State tax treatment of loan forgiveness differs; see the relevant state guide and a local tax advisor.
Accessibility
We aim to meet WCAG 2.1 AA expectations: semantic headings, sufficient color contrast, keyboard-navigable menus, and responsive layouts that work on phones and desktops alike. If you encounter a barrier, the corrections channel is the fastest way to reach us.
Corrections & How to Reach Us
We maintain a corrections policy: if a source changes, a formula is wrong, or a link is dead, we investigate and update the affected page, bumping its "Last Reviewed" date. Because this is a static site, the most reliable contact is through the project repository or the contact route published on the Terms of Use page. When you report an issue, please include the page URL and the specific number or statement so we can reproduce it.
No. StudLoanCalc is an independent, privately operated calculator. We are not affiliated with ED, MOHELA, or any loan servicer, and nothing on the site is an official government communication. We link to primary sources so you can verify everything yourself.
No. All calculations run in your browser. We do not create accounts, and no loan data is transmitted to our servers. Anything you save stays in your browser's local storage.
Policy parameters are stored in a single configuration file and are reviewed whenever ED publishes a new rule or rate. Major changes, such as the 2026 transition from SAVE to the RAP plan, trigger a prompt update, and the page review date reflects the latest check.
They are estimates to inform your thinking, not a substitute for the official studentaid.gov Loan Simulator or your servicer's statement. Always confirm material figures with those official sources before acting.
Advertising supports the site so it can remain free and private. We do not share your data with advertisers and we do not use affiliate links to lenders, so an ad never influences the calculations or warnings we show.
Report it through the contact route on our Terms of Use page, including the page URL and the specific figure. We investigate, correct the page, and update its review date. A transparent correction history is part of how we maintain accuracy.
No. The content is educational and based on published federal rules. It is not legal, tax, or financial advice. For decisions with significant consequences, consult a certified financial planner, tax professional, or qualified attorney.