Discretionary income calculator using both definitions: take-home pay minus essentials, or the federal poverty-guideline formula for student loans.
Discretionary Income Formula
In everyday budgeting, discretionary income is what remains of your take-home pay after essential living costs:
D = N - E
The federal definition used for income-driven student loan repayment compares annual income to the poverty guideline instead:
D = AGI - (P * G)
Variables:
- D is discretionary income (per month in the everyday formula, per year in the federal formula)
- N is monthly take-home (after-tax) income and E is essential monthly expenses
- AGI is adjusted gross income from your tax return
- G is the HHS poverty guideline for your household size and location (2025 guidelines: $15,650 for one person plus $5,500 per additional person in the 48 contiguous states; higher in Alaska and Hawaii)
- P is the protected percentage – 150% for most income-driven repayment plans, 100% for the Chapter 13 bankruptcy means test
Choose the definition at the top of the calculator. The everyday mode returns monthly, weekly, and annual discretionary amounts plus their share of income. The federal mode returns annual and monthly discretionary income and shows 10% of it – the payment rate many income-driven plans apply.
2025 Poverty Guidelines by Household Size
These are the HHS guidelines the federal calculation uses, for the 48 contiguous states and D.C. At 150%, this is the income shielded from income-driven repayment.
| Household size | Guideline (100%) | Protected at 150% |
|---|---|---|
| 1 | $15,650 | $23,475 |
| 2 | $21,150 | $31,725 |
| 3 | $26,650 | $39,975 |
| 4 | $32,150 | $48,225 |
| 5 | $37,650 | $56,475 |
| 6 | $43,150 | $64,725 |
Example Problems
Example 1: Everyday discretionary income.
Take-home pay is $4,800 per month and essentials total $3,100:
D = 4,800 – 3,100 = $1,700 per month, about 35% of take-home pay, or $20,400 per year to direct at wants, extra savings, and extra debt payments.
Example 2: Federal discretionary income for student loans.
AGI is $60,000, household of 2, in the 48 contiguous states, at 150%:
G = 15,650 + 5,500 = $21,150. Protected amount = 1.5 x 21,150 = $31,725. D = 60,000 – 31,725 = $28,275 per year. A plan charging 10% of discretionary income would set payments near $236 per month.
Frequently Asked Questions
What is the difference between disposable and discretionary income?
Disposable income is what remains after taxes – essentially your take-home pay. Discretionary income goes one step further and also subtracts necessities like housing, food, and insurance. Disposable pays for everything; discretionary is what is genuinely free to allocate.
Which expenses count as essential?
Housing, utilities, groceries, transportation to work, insurance, childcare you cannot skip, and minimum debt payments. Streaming services, dining out, hobbies, and vacations are discretionary by definition – the test is whether the spending could stop next month without breaking your household or your credit.
Why does my student loan servicer calculate a different number?
Servicers use the federal formula with your AGI, family size, and the poverty guideline year that applies to your recertification date, and specific plans differ in the protected percentage they use. This calculator uses the 2025 guidelines as a close estimate; your servicer’s figure at recertification governs the actual payment.
