Last verified 11 August 2026
Every rule the calculator applies is listed below with its source. Where the model makes an assumption rather than applying a rule, that is listed too, including the direction of the error. If a number here is wrong, the tool is wrong — so it is easier to check it than to trust it.
AGI at or below $10,000 pays a flat $120 a year. Above that the rate starts at 1% and rises one percentage point per additional $10,000 of AGI, capping at 10% above $100,000. Each dependent reduces the monthly payment by $50, never below the $10 floor.
Interest that a payment does not cover is waived rather than capitalised, so the balance cannot grow. If a payment reduces principal by less than $50, the Department of Education contributes the difference.
Forgiveness arrives at 360 qualifying payments. Parent PLUS loans cannot enter RAP.
Borrowers whose first federal loan predates 1 July 2014 use Old IBR: 15% of discretionary income, forgiveness at 25 years. Later borrowers use New IBR: 10%, forgiveness at 20 years. Payments are capped at the 10-year Standard amount. OBBBA removed the partial financial hardship requirement.
If every loan predates that date and you have not consolidated since, IBR remains available. A single newer loan, or a consolidation completed on or after that date, restricts you to RAP or Tiered Standard permanently.
The term is set by original balance: under $25,000 gets 10 years, $25,000–$49,999 gets 15, $50,000–$99,999 gets 20, and $100,000 or more gets 25. Minimum payment $50 a month. Time spent in the plan earns no PSLF credit.
The American Rescue Plan Act exclusion expired on 31 December 2025. A balance forgiven through an income-driven plan after that date is ordinary federal income in the year forgiven. PSLF forgiveness remains tax-free.
Roughly 7.5 million borrowers were still enrolled in SAVE. Servicers began mailing termination notices around 1 July 2026, each starting a 90-day window. Borrowers who do not choose are placed on Standard or Tiered Standard.
Published by HHS on 15 January 2026 for the 48 contiguous states and DC. Alaska is $19,950 (+$7,100) and Hawaii $18,360 (+$6,530). These drive the discretionary income calculation for IBR.
Rev. Proc. 2025-32. Married-filing-separately thresholds are the joint thresholds halved. Standard deductions: $16,100 single and MFS, $32,200 joint, $24,150 head of household.
Payments recalculate annually against the grown figures. Neither number is a forecast — they are conventional placeholders, and both are adjustable in the model.
Interest accrues on outstanding principal only and sits in a separate bucket. Real capitalisation events — leaving the plan, failing to recertify — make IBR worse than shown. The projection is therefore optimistic for IBR rather than alarmist, which is the safer direction for a tool people act on.
Projecting tax brackets and income 20 to 30 years forward is guesswork, so both are held constant. Federal only — state treatment varies and is not modelled.
The first three years of interest subsidy on subsidised loans is omitted, which again understates IBR slightly in the borrower-protective direction.
A plan is not recommended purely for winning on lifetime cost if its payment would exceed 15% of gross income. Borrowers leaving SAVE are frequently coming off a $0 payment, and advice they cannot act on is not advice.
Each plan is simulated month by month rather than approximated with a closed-form formula, because RAP's interest waiver and principal match cannot be expressed as simple amortisation. Payments recalculate annually. The engine is covered by 68 unit tests that assert every RAP bracket boundary, the published poverty tables, the Tiered Standard term tiers, forgiveness taxability and the deadline arithmetic.
The comparison runs entirely in your browser. Your loan balance and income are never transmitted anywhere — see the privacy policy.
Department of Education guidance is still being issued and these rules may change. If you find an error, email rogercramey@gmail.com and it will be corrected and the verification date updated.