IBR calculator

How the IBR payment is calculated

IBR's payment comes from four steps in the federal rule (34 CFR 685.209(b)(1), (f)(2)–(3) and (g)(1)(iii)):

1. Protected income. Take 150% of the HHS poverty guideline for your family size and state.
2. Income above it. Subtract that from your AGI, or from the joint AGI if you file a joint return.
3. The percentage. New IBR takes 10% of what is left, old IBR 15%. Divide by 12.
4. The limits. A result under $5 makes the payment $0, and $5 to $9.99 makes it $10. The payment never goes above the 10-year standard payment on the balance you had when you entered IBR.

The calculator opens on a single borrower with $55,000 of AGI and $35,000 of loans at 6.52%:

• 150% of the $15,960 guideline for one person is $23,940.
• $55,000 minus $23,940 leaves $31,060. 10% of that is $3,106 a year, or $258.83 a month.
• The 10-year standard payment on $35,000 at 6.52% is $397.78, so the cap doesn't apply yet. With a 3% yearly raise it applies from year 14.
• RAP would charge $229.17 for the same borrower.

On a joint return where your spouse also has federal loans, the payment is then split by each spouse's share of the couple's balances, as RAP's is.

2026 poverty guidelines and IBR's protected income

These are the 2026 HHS guidelines for the 48 states and DC (Federal Register, January 15, 2026), and the income IBR leaves alone at 150% of them:

Each additional person adds $5,680 to the guideline, which is $8,520 of protected income. Alaska's guideline is $19,950 plus $7,100 per extra person, and Hawaii's is $18,360 plus $6,530. Choose your state under "More details" in the calculator. HHS publishes new guidelines every year, so these figures change in 2027.

Family size: where IBR and RAP differ most

IBR counts your whole family through the guideline: you, a spouse if you file jointly, children who get more than half their support from you, and other dependents who live with you. RAP takes a flat $50 a month off for each dependent on your tax return.

Each extra person lowers a new-IBR payment by $71 a month (10% of $8,520, divided by 12) and an old-IBR payment by $106.50, as long as the payment is above $0 and under its cap. RAP drops by $50 a month for each dependent on your tax return.

For a single parent with two children, $48,000 of AGI and the same $35,000 at 6.52%, IBR is $58.50 a month and RAP is $60, nearly the same. The difference is what happens to the interest. Neither payment covers the $190.17 of interest charged in the first month.

• Under IBR the unpaid interest is still charged. The balance grows to about $56,300, which is forgiven after 20 years. At a 22% tax rate, the tax on that is about $12,400.
• Under RAP the unpaid interest is waived and principal is matched, so the balance falls every month. The loan is paid off in 246 payments, for about $57,700 in total.

IBR costs less in total here, about $36,700 including the estimated tax, but it leaves a tax bill at the end and a balance that grows for 20 years.

New IBR or old IBR

• New IBR is for "new borrowers": no federal loan balance before July 1, 2014. It takes 10% of income above 150% of the guideline and forgives what's left after 240 payments (20 years).
• Old IBR is for everyone else: 15% of the same income, forgiven after 300 payments (25 years).

Both are capped at the 10-year standard payment. On the calculator's example, old IBR would be $388.25 a month instead of $258.83. Untick "New IBR" under "More details" to switch.

Who can use IBR in 2026

• Loans made before July 1, 2026 only. Any Direct Loan made on or after that date, including a Direct Consolidation Loan, limits all your loans to RAP or the Tiered Standard plan. Going back to school or consolidating now closes IBR.
• Not after 60 SAVE payments. A borrower who made 60 or more qualifying payments under SAVE on or after July 1, 2024 can't enroll in IBR.
• From PAYE or ICR. Borrowers on either plan can move to IBR, and PAYE and ICR payments made before July 1, 2028 count toward IBR's forgiveness. Anyone still on PAYE or ICR on July 1, 2028 is moved to RAP, or to IBR for loans RAP can't take.
• Parent PLUS loans follow separate rules. See Parent PLUS loans under the 2026 rules.

IBR and RAP: the differences that decide

• Interest. IBR charges the interest your payment doesn't cover, and adds it to your balance when the payment reaches the cap or you leave IBR. RAP waives it on every on-time payment and matches principal up to $50.
• Cap and floor. IBR can be $0 and never goes above the 10-year standard payment. RAP never goes below $10 and has no cap.
• Forgiveness. IBR forgives after 20 or 25 years, RAP after 30. Both are taxed after 2025; PSLF isn't.
• The count runs one way. IBR payments count toward RAP's 360 if you switch later. RAP payments don't count toward IBR's 20 or 25 years, except payments at least as large as the 10-year standard amount and qualifying PSLF payments.

The RAP vs IBR calculator puts both beside the standard plans, with the total cost of each.

IBR, PAYE and ICR

IBR stays open for older loans alongside RAP. PAYE and ICR remain only for borrowers already on them, until June 30, 2028:

IBR vs PAYE: for a new borrower, the formula and the 20-year clock are the same, so the payment is the same. PAYE's months count toward IBR forgiveness and toward RAP's 360, so moving from PAYE to IBR before 2028 keeps your count. If you had a federal loan balance before July 1, 2014, your IBR would be old IBR, 15% for 25 years.

IBR vs ICR: ICR protects income only up to 100% of the guideline, against IBR's 150%, and takes 20% of the income above it. It also has a second formula, a 12-year payment scaled by an income factor, and charges the lower of the two. Which plan is lower depends on your income and balance.

What the calculator assumes

Payments are on time and the rate is fixed. Income rises by your expected raise each year, and the payment is recalculated yearly. The poverty guideline grows with the inflation input, your family size stays as entered, and there are no deferments or forbearances. IBR's extra interest help in the first three years on subsidized loans isn't modeled. Your servicer's calculation decides the real payment. Sources and methods lists every rule.