US Finance Calculators Income-Driven Repayment Calculator

US Finance Calculators is a hub of over 220 free financial calculators, and the income-driven repayment (IDR) tool stands out as one of the most sophisticated student loan calculators you can run without signing up or paying anything. The calculator is built for Americans, explicitly advertised as 100% free and requiring no signup. It is not a bank or broker's marketing tool, it is an independent calculator website.

Most student loan calculators show you a monthly payment. This one models your full repayment path across every available federal income-driven plan, projects 25-year costs in today's dollars, and factors in your household filing strategy so you can actually pick the right plan instead of just the cheapest one this month. It handles complexity that most borrowers never model: whether to file taxes as Married Filing Jointly or Married Filing Separately, how spousal income affects your payment, whether to pursue Public Service Loan Forgiveness instead of paying it off, and where private refinancing makes sense versus staying federal.

What the Calculator Actually Models

The tool asks for four core inputs to start: your federal loan balance, weighted average interest rate, current AGI, and family size. From there it lets you add optional fields like your spouse's income and federal loan balance if you are married, your target income growth rate, whether you work for a PSLF-eligible employer, and what discount rate you want to use for present-value cost modeling. You can also enter an estimated tax rate on forgiven amounts (the "tax bomb" if your loans are forgiven after 20 or 25 years outside of PSLF).

Once you click Run Workbench, the calculator generates a color-coded strategy verdict with six KPI panels, a year-by-year payment path chart, a present-value cost comparison chart, and a full strategy table that compares every plan side-by-side across current payment, total paid, forgiveness year, forgiven amount, tax exposure, and present-value cost. That table is the thing most calculators skip: showing you what the total lifetime cost of each path actually is, not just this month's payment.

The Five Federal Plans It Compares

The calculator models all five income-driven plans currently available:

SAVE (Saving on a Valuable Education) uses 5% of discretionary income for undergraduate loans and 10% for graduate loans, with income measured as your AGI minus 225% of the federal poverty line. Forgiveness happens in 10 years if your balance is $12,000 or less, otherwise 20 to 25 years. It is available to new and existing borrowers and is generally the lowest ongoing payment.

PAYE (Pay As You Earn) uses 10% of discretionary income capped at what the Standard 10-year payment would be, with income measured as AGI minus 150% of poverty line. Forgiveness is 20 years. It is limited to new borrowers (those who first took a federal loan after October 1, 2007) but comes with an advantage when you file taxes separately: your spouse's income is excluded from the payment calculation.

IBR (Income-Based Repayment) comes in two versions. The newer version available to borrowers after July 1, 2014 uses the same 10% formula as PAYE. The original version, still available to older borrowers, uses 15% of discretionary income with a 25-year forgiveness timeline. Both are available to all borrowers.

ICR (Income-Contingent Repayment) uses 20% of discretionary income or a fixed 12-year payment amount, whichever is lower, with income measured as AGI minus 100% of poverty line. Forgiveness is 25 years. It is available to all borrowers and is often the only option for Parent PLUS borrowers who have consolidated to Direct Loans.

Standard is the old-fashioned 10-year fixed payment with no income consideration, and it qualifies for PSLF if you make exactly 120 payments.

The calculator shows which plans offer PSLF compatibility and whether spousal income is counted or excluded under each plan, because that gap is where many borrowers find thousands in lifetime savings.

The Household Filing Strategy Layer

This is where the tool gets genuinely useful. If you are married, your filing status (Married Filing Jointly versus Married Filing Separately) can swing your IDR payment by hundreds of dollars per month because some plans exclude spousal income when you file separately. The calculator models both paths and shows you the net result after factoring in the tax penalties from filing separately (which you lose various deductions and credits).

In one scenario the calculator walks through, a married couple with a non-profit employee and a private-sector spouse found that filing separately dropped the IDR payment by $650 per month, a $7,800 yearly savings. But filing separately also cost about $7,200 per year in lost tax benefits. The net winner was filing separately by a small margin that grows over time. A borrower running the calculator themselves can see their own numbers instead of guessing.

PSLF and Private Refinance Breakpoints

The calculator shows you when private refinancing makes sense and when it does not. If you are pursuing Public Service Loan Forgiveness, refinancing to a private lender permanently removes your loans from all federal programs and erases your PSLF progress entirely. There is no way to return to federal status after that. The calculator models the PSLF timeline and shows whether staying federal or refinancing saves money in your specific situation.

For borrowers not pursuing PSLF (typically private-sector employees), the calculator compares staying on an IDR plan for 20-25 years versus refinancing to a private loan at a lower rate. It shows the breakeven point, whether saving interest over a shorter private term outweighs the forgiveness you lose by exiting the federal system.

What It Does Not Do

The calculator does not connect to your bank. There is no account creation, no transaction tracking, no integration with your actual loans. It is a planning model, explicitly labeled as such. It does not pull your real loan servicer data or verify that the inputs you enter are correct, that is your job. It does not make the decision for you; it shows you what the decision would cost under your circumstances.

The site publishes that SAVE plan was subject to ongoing federal court litigation in 2025 and 2026, and borrowers enrolled in SAVE may be in a forbearance period. It directs you to StudentAid.gov for the latest status before selecting SAVE as your primary strategy.

Real-World Walkthroughs

The calculator includes three full scenarios worked through. One walks a public school teacher with $78,000 in debt at 6.5% interest, $52,000 AGI, three years of qualifying PSLF payments made, and seven years remaining to forgiveness. The calculator shows her SAVE payment would be roughly $142 per month, total payments over 7 more years around $11,900, with roughly $82,000 forgiven tax-free. If she switched to Standard 10-year she would pay $880 a month and $105,600 total, PSLF saves her over $93,000.

The second scenario is a physician in private practice with $310,000 in graduate loans, $240,000 AGI, no PSLF eligibility. The calculator shows that refinancing to a 6.1% private rate on a 10-year term saves roughly $44,000 in total interest versus staying on IBR for 25 years. But it marks this as a "Refinance Breakpoint": worth doing only if income is stable, because refinancing sacrifices the safety net of income-driven protection if circumstances change.

The third walks a married couple through Married Filing Jointly versus Married Filing Separately, showing the monthly payment difference ($1,240 versus $590) and modeling whether the $600-per-month payment savings outweighs the tax penalties.

Who It Suits

This is for a federal student loan borrower (not Parent PLUS in its current form, and not private loans, which have no income-driven option) who wants to model the full lifetime cost of different strategies before deciding what to do. It is particularly useful if you are married and considering whether your spouse's income should count in the calculation, if you work for a non-profit or government employer and might pursue PSLF, or if you are deciding whether refinancing to a private lender makes sense. It is not a replacement for reading the Federal Student Aid website or talking to your loan servicer, but it lets you run the math yourself and see the impact of different choices before you commit to them.

The calculator is ad-supported or content-supported rather than sold, sitting on a site that publishes over 220 financial tools. There is no paywall and no trial limit. You can run as many scenarios as you need to understand your options.