About this tool
Income-Driven Repayment (IDR) plans set your federal student loan payment based on AGI and family size, not the size of the balance. The three options here, IBR, PAYE, and SAVE, all subtract a multiple of the federal poverty line from AGI and apply a percentage to what is left. SAVE uses 225 percent of poverty and 5 percent on undergraduate balances, generally producing the lowest payment.
How it works
The 2025 federal poverty line for a single household in the contiguous 48 states is $15,650, with about $5,500 added per additional family member. IBR and PAYE multiply that by 1.5; SAVE by 2.25. Your discretionary income is the remainder, and the plan applies its rate to produce the annual payment.
How to use the Student Loan IDR Calculator
The Student Loan IDR Calculator is a browser-based tool that runs entirely on your device. Inputs you enter never reach a server - all calculations happen client-side in JavaScript. This means:
- Privacy: nothing is logged, sent, or stored by 3Tej. Inputs disappear when you close the tab.
- Speed: results update as you type. No network round trip.
- Offline use: once the page is cached, it works without internet.
- No signup: no account, no email, no rate limits.
Step by step
- Enter your inputs in the form above. Each field is labeled with its unit (currency, percent, kg, etc.) and the expected range.
- Read the result as it updates. The number reflects the formula commonly accepted in Student Loan IDR-related calculations.
- Adjust to see sensitivity: change one input at a time and watch how the output moves. This is the fastest way to understand which variable matters most.
- Copy or screenshot the result for later reference. The page state persists for the session if your browser allows it.
When you would use this
- Quick estimates: when you need a number now and don't want to open a spreadsheet.
- Sensitivity analysis: testing how a result changes as inputs vary, before committing to a real-world decision.
- Comparison: running the same calculation with different inputs to compare options side by side.
- Learning: building intuition for how the underlying math behaves.
- Documentation: capturing a snapshot of inputs and outputs at a point in time.
The formula explained
This calculator uses the following formula:
Discretionary income = AGI - (poverty line × multiplier). Monthly payment = Discretionary × plan rate ÷ 12.
The reason this formula works is rooted in the underlying physics, finance, or biology of the problem. Behind every calculator is a published, peer-reviewed equation or a widely accepted convention. We do not invent formulas; we apply standard ones from textbooks, government tables, professional bodies, and academic literature.
If you are curious about the math, the simplest way to verify is to plug in two known numbers and compare against a known result. The calculator should match published examples to within rounding precision.
Frequently asked questions
What is discretionary income?
AGI minus a multiple of the federal poverty line for your family size. IBR and PAYE use 150 percent of poverty; SAVE uses 225 percent of poverty for undergraduate loans.
Which IDR plan is best?
SAVE generally has the lowest payments due to the 225 percent poverty exclusion and 5 percent rate on undergraduate balances. PAYE caps at 10 percent and forgives in 20 years; IBR caps at 10 to 15 percent depending on borrowing date.
How is family size counted?
You, plus your spouse if you file jointly, plus children and other dependents you support. Larger family size means a larger poverty exclusion, which lowers the payment.
Are IDR payments recertified?
Yes. You must recertify income and family size each year so the servicer can recompute the monthly amount based on the latest AGI.
Is the Student Loan IDR Calculator accurate?
The Student Loan IDR Calculator applies the standard formula for student loan idr. Accuracy is limited only by your input precision. For decisions with material consequences, use the result as a starting point and verify with a qualified professional or the relevant official source.
Is the Student Loan IDR Calculator free?
Yes. 100% free, no signup, no payment, no API key. The site is funded by display ads that appear around the tool but not inside the calculation flow.
Are my inputs saved?
No. Inputs stay in your browser tab. Closing the tab discards them. The site uses Google Analytics for traffic measurement (anonymized) but does not see what you type into the form.
Can I use the Student Loan IDR Calculator on my phone?
Yes. The tool is responsive and tested on iOS Safari, Android Chrome, and major desktop browsers. Touch targets meet Apple's 44pt and Google's 48dp minimum guidance.
How do I report a bug or suggest improvement to the Student Loan IDR Calculator?
Email hi@3tej.com with the URL of this page and a description of what you saw vs expected. We typically respond within 72 hours and update calculators when rules or formulas change.
How accurate is the Student Loan IDR Calculator?
It applies the standard formula. Accuracy is limited only by your input precision. For decisions with material consequences (taxes, medical, legal, structural), use the result as a starting point and verify with a qualified professional in the relevant field.
Is the Student Loan IDR Calculator free to use?
Yes. 100% free, no signup, no payment, no API key. The site is funded by display ads around the tool but not inside the calculation flow.
Are my inputs saved anywhere?
No. All inputs stay in your browser tab. Closing the tab discards them. The site uses Google Analytics for traffic measurement (anonymized) but the analytics never see what you type into the form.
Does the Student Loan IDR Calculator work offline?
Yes. Once the page has loaded, it works without internet. The calculation runs in JavaScript on your device.
Can I share results from the Student Loan IDR Calculator?
Take a screenshot or copy the output. The page doesn't generate shareable URLs for specific calculations - inputs stay in your browser only.
Why are the results different from another student loan idr tool?
Most likely: different formula assumptions, different default values, different rounding rules, or different applicable rates. Check the methodology if both tools document it. Both can be valid for different scenarios.