Estimate your monthly student loan payments with our free Income-Driven Repayment (IDR) Discretionary Income Calculator. Quickly calculate your discretionary income to discover your lowest payment options under SAVE, PAYE, and IBR plans. Take control of your student debt today!
IDR Discretionary Income Calculator
Federal Poverty Guideline (FPG):
Protected Income Excluded:
Annual Discretionary Income:
Monthly Discretionary Income:
What is the exact definition of discretionary income for federal student loans?
For federal student loans, discretionary income is defined as the difference between your annual income and a specific percentage of the Federal Poverty Guideline (FPG) based on your family size and state of residence.
Unlike the standard economic definition of discretionary income (money left over after taxes and basic necessities), the Department of Education uses a strict, standardized formula to determine how much you can afford to pay under Income-Driven Repayment (IDR) plans. The portion of your income that exceeds the protected FPG threshold is considered your discretionary income, and your monthly student loan payment is calculated as a fixed percentage (typically 5% to 20%) of this leftover amount.
How is discretionary income mathematically calculated for IDR plans?
The mathematical calculation for discretionary income involves two main components: your Adjusted Gross Income (AGI) and the Federal Poverty Guideline (FPG) for your family size and location.
- Identify your AGI from your most recent federal tax return.
- Find the current FPG for your specific family size and state.
- Multiply the FPG by the percentage dictated by your specific IDR plan (e.g., 150% or 225%).
- Subtract the result of Step 3 from your AGI.
Formula: Discretionary Income = AGI - (FPG × Plan Percentage)
If the result is a negative number, your discretionary income is automatically considered $0.
Which federal poverty guideline percentage applies to my specific repayment plan?
The percentage of the Federal Poverty Guideline (FPG) protected from the calculation depends strictly on your chosen Income-Driven Repayment (IDR) plan. Here is the breakdown:
| Repayment Plan | Protected FPG Percentage |
|---|---|
| SAVE (Saving on a Valuable Education) | 225% |
| PAYE (Pay As You Earn) | 150% |
| IBR (Income-Based Repayment) | 150% |
| ICR (Income-Contingent Repayment) | 100% |
Plans with higher protected percentages, like SAVE, result in lower discretionary income and lower monthly payments.
How does my family size impact my discretionary income calculation?
Your family size directly impacts the baseline Federal Poverty Guideline (FPG) used in your calculation. As your family size increases, the poverty guideline amount increases.
Because discretionary income is calculated by subtracting a percentage of the FPG from your income, a larger family size results in a much larger deduction. Consequently, this lowers your calculated discretionary income and reduces your monthly loan payment. For federal student loans, family size generally includes you, your spouse (depending on your tax filing status), and any children or other dependents who receive more than half of their financial support from you.
Does my state of residence alter the poverty guidelines used for my calculation?
Yes, your state of residence alters the Federal Poverty Guidelines (FPG) used for your calculation. The Department of Health and Human Services issues three distinct sets of poverty guidelines based on location:
- The 48 Contiguous States and D.C.: Uses the baseline standard guideline.
- Hawaii: Uses a moderately higher FPG compared to the contiguous states.
- Alaska: Uses the highest FPG to account for the highest cost of living.
If you live in Alaska or Hawaii, your protected income threshold will be higher. This reduces your discretionary income and results in a lower monthly student loan payment compared to someone with the exact same income and family size living in another state.
How does the SAVE plan increase the discretionary income exemption?
The SAVE (Saving on a Valuable Education) plan increases the discretionary income exemption by protecting a significantly larger portion of your earnings compared to older plans. While older plans like PAYE and IBR protect 150% of the Federal Poverty Guideline (FPG), the SAVE plan protects 225% of the FPG.
By increasing this multiplier to 225%, the SAVE plan shields roughly the equivalent of a $15 per hour wage for a single borrower. This means a much larger chunk of your Adjusted Gross Income is deducted before calculating your payment, heavily reducing your discretionary income and drastically lowering monthly payments for most borrowers.
Is discretionary income based on my gross salary or my Adjusted Gross Income?
Discretionary income for federal student loans is primarily based on your Adjusted Gross Income (AGI), not your gross salary. Your AGI is found on your federal income tax return and is typically lower than your gross salary because it accounts for specific deductions, such as retirement contributions, health insurance premiums, and student loan interest deductions.
However, if your AGI does not accurately reflect your current financial situation (for example, due to recent job loss, a significant pay cut, or a change in marital status), you can submit alternative documentation, such as recent pay stubs. In those specific scenarios, your servicer may estimate your income based on your current gross earnings rather than your past AGI.
How does my tax filing status determine if my spouse's income is included?
Your federal tax filing status dictates whether your spouse's income is factored into your discretionary income calculation:
- Married Filing Jointly (MFJ): Your loan servicer will use your combined joint AGI. Both your income and your spouse's income will be used to calculate your discretionary income, regardless of who holds the student loan debt.
- Married Filing Separately (MFS): Under most modern IDR plans (including SAVE, PAYE, and IBR), if you file separately, your discretionary income is calculated using only your individual AGI. Your spouse's income is legally excluded.
Filing separately can drastically reduce your student loan payment if your spouse earns an income, but it may disqualify you from certain tax benefits. You should evaluate both scenarios.
What happens to my monthly payment if my discretionary income is calculated as zero?
If your calculation results in a discretionary income of zero—or a negative number—your required monthly student loan payment will be exactly $0.
A $0 payment is an official, legitimate payment under Income-Driven Repayment (IDR) plans. The benefits of a $0 payment include:
- Forgiveness Credit: Every month of a $0 payment fully counts toward the 20 or 25 years required for IDR loan forgiveness, as well as Public Service Loan Forgiveness (PSLF).
- Interest Subsidies: Under plans like SAVE, if your calculated payment is $0, the government subsidizes 100% of the unpaid monthly interest, preventing your overall loan balance from growing.
How often must I recertify my income to update my discretionary income amount?
You must generally recertify your income and family size annually to keep your discretionary income amount updated and your IDR plan active.
Your loan servicer will send a reminder before your deadline. If you fail to recertify on time, your monthly payment will typically revert to the Standard Repayment Plan amount, which is usually significantly higher. Additionally, unpaid interest may capitalize.
While annual recertification is required, you can request to recalculate your payment at any time if your income drops or your family size increases before your annual deadline. Borrowers can also opt-in to automatic annual recertification by granting the Department of Education access to their IRS tax data.
Sources:
Student Loan Refinancing Origination Fee Calculator