Income-Driven Repayment Calculator
Income, threshold & plan
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- United States card and lending practice
- Scope and limitations
- Educational estimate only. Your issuer sets the minimum-payment formula, how a payment is allocated across balances, when interest is charged, and any fees or promotional terms — check your cardholder agreement for the figures that bind.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter your annual income and household poverty line.
- 02
Set the protected multiple and the plan percentage.
- 03
See your estimated monthly payment.
Formula
discretionary income = max(0, AGI - povertyLine x multiplier); annual payment = discretionary income x (planPct / 100); monthly payment = annual payment / 12. The protected amount is povertyLine x multiplier, and the max(0, ...) clamp means the payment falls to zero whenever AGI is at or below that protected amount, because there is no income above the threshold to charge against. The loan balance never enters the calculation.
Example
Suppose you enter an annual income (AGI) of $50,000, a household poverty line of $15,650 - the federal guideline for a one-person household in the 48 contiguous states - a protected multiple of 1.5, and a plan percentage of 10%. Step 1 - protected amount: poverty line x multiple = $15,650 x 1.5 = $23,475. This much income is shielded from the payment calculation. Step 2 - discretionary income: max(0, AGI - protected amount) = max(0, $50,000 - $23,475) = $26,525. Only this portion, the income above the protected line, is available for payments. Step 3 - annual payment: discretionary income x plan percentage = $26,525 x 10% = $2,652.50. Step 4 - monthly payment: $2,652.50 / 12 = $221.04. So the headline monthly payment is $221.04, with an annual payment of $2,652.50 and discretionary income of $26,525. Note that the protected $23,475 is charged nothing, and the loan balance played no part in any step - which is the point of an income-driven plan, and also why a large balance can keep growing while you pay on time. If income instead fell to $23,475 or below, discretionary income would clamp to 0 and the payment would be zero.
Definitions
- Annual income (AGI)
- The yearly income figure the payment is built from; income at or below the protected amount produces a zero payment, and every unit above it adds to discretionary income (0 to $1,000,000).
- Poverty line (household)
- The household poverty figure for your family size; multiplied by the protected multiple it sets the protected amount, so a larger household raises it and lowers the payment (0 to $100,000).
- Protected multiple
- How many times the poverty line is shielded before any income counts toward a payment; a higher multiple protects more income and shrinks the payment (1 to 4, default 1.5).
- Plan percentage
- The share of discretionary income charged as the annual payment; it scales the result linearly, so it applies only to income above the protected amount, never to total income (5% to 20%, default 10%).
- Discretionary income
- Income above the protected amount, calculated as max(0, AGI - poverty line x multiple); it is clamped at zero and is the only figure the plan percentage is applied to.
- Monthly payment
- The headline result: discretionary income times the plan percentage, divided by twelve; it is set entirely by income, the protected amount, and the plan rate, not by the loan balance.
Good to know
What an income-driven payment really measures
An income-driven payment is built on a simple idea: the amount you owe each period should track what you can afford, not the size of your loan balance. Instead of dividing the balance over a fixed term, the calculator starts from your income and protects a slice of it tied to a poverty figure, then charges a fixed percentage of whatever income sits above that protected slice. The protected slice is the household poverty line multiplied by a protected multiple, and only income beyond it is treated as available for payments. This is why two borrowers with identical balances can owe very different amounts: the one earning more above the protected line has more discretionary income, so the same plan percentage produces a larger payment. The balance itself never enters this calculation. It governs how long you keep paying and how much interest accrues, but the per-period figure is set entirely by income, the protected amount, and the plan rate. That separation is the defining feature of these plans and the reason they are described as income-driven rather than balance-driven. It also means the payment can rise and fall over the years as your earnings change, rather than staying flat the way a standard amortized payment does. The calculator captures a single snapshot: it takes the income, protected amount, and plan rate you enter and returns the payment that combination implies right now, which is the starting point for understanding how the plan behaves over a longer horizon as circumstances shift.
How discretionary income is defined
Discretionary income is the engine of the whole calculation, and it is narrower than the everyday meaning of the phrase. Here it is a precise quantity: your income minus a protected amount equal to the household poverty line times a protected multiple. With a poverty line of 150,000 and a multiple of 1.5, the protected amount is 225,000, so on an income of 600,000 the discretionary figure is 600,000 minus 225,000, or 375,000. Everything below 225,000 is shielded; only the 375,000 above it is considered available for loan payments. The protected multiple is what makes this generous rather than punitive. A multiple of 1.5 means you keep one and a half times the poverty line before any income counts toward a payment, and raising the multiple shields more income, shrinking discretionary income and therefore the payment. The household poverty line is not a fixed personal number either; it reflects family size, so a larger household has a higher poverty line, a larger protected amount, and a smaller discretionary figure for the same income. This is deliberate: a given income stretches less far across more people, so the plan protects more of it. Understanding discretionary income as income minus poverty line times multiple, rather than as some loosely defined leftover spending money, is the key to reading every other number the calculator produces, because the plan percentage is applied to this figure alone and nothing else feeds the payment.
Turning discretionary income into a payment
Once discretionary income is known, the payment is straightforward: multiply discretionary income by the plan percentage to get the annual payment, then divide by twelve for the monthly figure. With 375,000 of discretionary income and a 10% plan, the annual payment is 37,500 and the monthly payment is 3,125. The plan percentage is the single dial that scales the whole result. A plan that charges 10% of discretionary income produces a payment exactly half the size of one charging 20% on the same income, because the percentage applies linearly to the discretionary figure. This is why the plan rate matters so much when comparing options: a few percentage points translate directly into a proportional change in what you pay each month. The percentage is applied only to discretionary income, never to total income, so even a 20% plan still charges nothing on the protected portion. In the example, the 10% plan leaves the protected 225,000 untouched and charges 10% only on the 375,000 above it. Reading the result this way makes the levers obvious: lowering income, raising the protected multiple, or choosing a lower plan percentage each reduces the payment, while the loan balance plays no part in the figure at all. The annual-then-monthly structure also reflects how these plans are administered in practice, where eligibility and payment amounts are usually assessed on an annual income figure and then spread across the year as twelve equal installments.
Why the payment can fall to zero
The most distinctive behavior of an income-driven payment is that it can fall all the way to zero. The formula clamps discretionary income at a floor of zero, so if your income is at or below the protected amount, there is no income above the protected line to charge against, and the payment is nothing. With a protected amount of 225,000, anyone earning 225,000 or less has zero discretionary income and therefore a zero payment, no matter how large the loan. This is not a loophole or an error; it is the intended design. The plans exist precisely so that borrowers with little income are not forced into payments they cannot make. As income rises above the protected line, the payment climbs from zero, starting small because only the first units of income above the threshold are charged. Just above 225,000, discretionary income is tiny, so a 10% plan charges almost nothing; the payment grows steadily as income pulls further above the protected amount. This produces a gentle on-ramp rather than a cliff. A borrower whose income dips during a hard year sees the payment shrink automatically, and one whose income recovers sees it rise again, all without renegotiating the loan. The zero-payment floor is the clearest expression of the plan's purpose: protection is built into the arithmetic itself, so the formula can never demand a payment from income that has been designated as protected, which is what separates these plans from fixed schedules that keep demanding the same amount regardless of hardship.
Why the payment changes year to year
Because the payment is driven by income, it is not a one-time calculation but something reassessed periodically as your circumstances change. In practice these plans require you to recertify your income, typically once a year, and the payment is recalculated from the income and household details you report. The calculator models a single point on that path, but the real plan is a series of such snapshots stitched together over many years. If your income grows, the next recertification produces a larger discretionary figure and a higher payment; if it falls, or if your household grows and lifts your poverty line, the payment drops. This responsiveness is the plan's main advantage and the reason it suits borrowers with uncertain or rising incomes. It also means the figure this tool shows is a current estimate rather than a fixed obligation for the life of the loan. Someone early in a career might start with a very low or zero payment, watch it climb as earnings rise, and eventually reach a point where the income-driven amount approaches or exceeds what a standard schedule would charge. Treating the payment as a moving target rather than a constant is essential to using these plans well, because budgeting around today's number alone can mislead you about what later years will demand. The annual recertification cycle is also where missing a deadline can matter, since failing to update your income can disrupt the calculation, but the underlying logic is always the same: each year's payment is rebuilt from that year's income and protected amount.
Forgiveness after a long repayment period
A central feature of these plans is the possibility of forgiveness after a long period of qualifying payments. Because the payment is capped at a share of discretionary income rather than sized to retire the balance over a set term, there is no guarantee the loan is fully repaid within any particular number of years. To resolve this, income-driven plans typically forgive whatever balance remains after a long stretch of payments, often on the order of twenty to twenty-five years. This is what makes a permanently low payment sustainable: a borrower who pays a small income-driven amount for decades, never clearing the principal, can have the remaining balance cancelled at the end of the forgiveness period. Forgiveness reframes how to think about the running balance. On a standard loan, a balance that is not shrinking is a warning sign; on an income-driven plan heading toward forgiveness, it can be an expected and even rational outcome, because the goal is affordable payments over time rather than the fastest possible payoff. The trade-off is the long horizon. Reaching forgiveness usually means staying enrolled, recertifying income each year, and making qualifying payments consistently across the full period, which can span most of a working life. The calculator does not project the forgiveness date, but understanding that the plan is built around eventual cancellation explains why a payment far too small to clear the balance can still be a coherent strategy rather than a path to indefinite debt that simply never ends.
Negative amortization when payments fall short
The flip side of a capped payment is negative amortization, which happens when the income-driven payment is smaller than the interest accruing on the loan. Interest is charged on the outstanding balance regardless of how the payment is calculated, so if the payment covers only part of the interest, the unpaid portion is added to what you owe and the balance grows even while you pay every month. This is the long-tail issue that surprises borrowers most: doing everything right and still watching the balance climb. It is a direct consequence of separating the payment from the balance. When income is low, the discretionary figure is small, the payment is small, and it may fall short of the interest that a large balance generates. The gap between interest charged and payment made is the amount by which the balance rises that period. Negative amortization is not a malfunction; it is the arithmetic result of paying less than the interest due. It matters because it changes the meaning of a low payment. An affordable monthly figure can coexist with a balance that is steadily increasing, and a borrower focused only on the payment may not notice the principal moving the wrong way. For those heading toward forgiveness, a growing balance may be tolerable because it will eventually be cancelled. For those who expect to repay in full, persistent negative amortization is a signal that the plan is delaying rather than reducing the debt, and that the eventual cost depends heavily on how long the shortfall lasts and how large it grows.
How unpaid interest capitalizes
Closely related to negative amortization is interest capitalization, the moment when accumulated unpaid interest is folded into the principal balance. While interest goes unpaid under a capped payment, it usually accrues as a separate running total. Capitalization is the event that converts that accrued interest into principal, after which future interest is charged on the new, larger balance, including the interest that was just added. This is the mechanism that can make a long stretch of low payments more expensive than the payment figures alone suggest. Capitalization tends to occur at specific triggers rather than continuously, such as leaving or switching plans or failing to recertify, and each time it happens the balance steps up and the interest charged from then on rises with it. The compounding effect is what gives capitalization its bite. A modest amount of unpaid interest, capitalized once and then accruing interest itself, grows faster than simple interest would, so two borrowers with the same payment history can end up with different balances depending on how often capitalization was triggered. The calculator does not track this directly, but it is the natural consequence of a payment that does not cover interest: the shortfall has to go somewhere, and capitalization is where it lands. Understanding it explains why the same low monthly payment can be relatively harmless for one borrower and costly for another. The payment is only half the picture; the other half is how the unpaid interest behaves over the years, and capitalization is the rule that governs how that unpaid interest compounds into a larger debt over time.
How sensitive the payment is to each input
Pulling the levers of the calculator shows how sensitive the payment is to each input, and which changes matter most. Income is the most direct lever: every unit of income above the protected amount adds directly to discretionary income, so a change in earnings moves the payment one-for-one through the plan percentage. The protected multiple is the next most powerful, because it scales the protected amount; raising it from 1.5 to 2.0 on a 150,000 poverty line lifts the protected amount from 225,000 to 300,000, cutting discretionary income on a 600,000 income from 375,000 to 300,000 and reducing a 10% payment from 3,125 to 2,500 a month. The household poverty line works the same way through family size, with a larger household raising the protected amount and lowering the payment. The plan percentage scales the final result directly, so doubling it doubles the payment while halving it halves the payment. What never moves the payment is the loan balance, which is the single most important thing to internalize about these plans and the most common point of confusion. By adjusting the four inputs and watching the discretionary figure and payment respond, you can map out how the plan would treat different earnings, family sizes, and plan rates. This makes the calculator useful not just for a single estimate but for understanding the shape of the whole plan: where the payment hits zero, how steeply it rises with income, and how protective the threshold is at the multiple you have chosen for your situation.
Reading the income-driven payment in context
It helps to place an income-driven payment against the fixed payment you would otherwise face, since the two are built on opposite logic. A fixed schedule sizes the payment to clear the balance over a set term, so the balance always shrinks and the payment stays the same regardless of income. An income-driven payment sizes itself to income, so it can be far lower, can be zero, and may not shrink the balance at all. The right comparison is not which payment is smaller this month but how each behaves over the full life of the loan. The income-driven payment offers protection and flexibility: it cannot demand more than the plan percentage of discretionary income, it falls automatically when income drops, and it carries the prospect of forgiveness at the end of a long period. The cost of that flexibility is the possibility of a growing balance, capitalized interest, and a much longer repayment horizon. For a borrower with a high income relative to their balance, the income-driven figure may end up close to or above a standard payment while taking longer, in which case the protection is mostly unused. For a borrower with a low income relative to a large balance, the same plan can mean small payments for years and eventual forgiveness. The calculator's job is to make the income-driven side of that comparison concrete, showing exactly what the plan would charge today given your income, protected amount, and plan rate, so the longer-term trade-offs can be weighed with a real number rather than a guess about what an income-tied payment might look like.
Frequently asked questions
Why does the calculator ignore my loan balance?
Because an income-driven payment is sized to what you earn, not what you owe. The payment is a share of discretionary income, so the balance only affects how long you pay and how much interest accrues, never the per-period figure itself.
Why can the payment be zero?
Discretionary income is clamped at a floor of zero. If your income is at or below the protected amount (poverty line times multiple), there is no income above the threshold to charge against, so the payment is nothing no matter how large the loan.
What happens to my payment if my income changes?
It moves with your income. These plans are recertified periodically, usually yearly, and the payment is recalculated from your reported income and household details, so it rises when you earn more and falls when you earn less or your household grows.
Can my balance grow even while I pay every month?
Yes. If the capped payment is smaller than the interest accruing on the loan, the unpaid interest is added to what you owe and the balance increases. This negative amortization is the arithmetic result of paying less than the interest due.
What is interest capitalization on these plans?
It is when accumulated unpaid interest is folded into the principal balance. After capitalization, interest is charged on the new larger balance, so unpaid interest begins to compound, which can make a long stretch of low payments more costly than the payment figures alone suggest.
Is the remaining balance ever forgiven?
Income-driven plans typically forgive whatever balance remains after a long period of qualifying payments, often around twenty to twenty-five years. This is why a payment too small to clear the balance can still be a coherent strategy rather than endless debt.