What is adjusted gross income (AGI)?
Adjusted gross income is your total income minus a specific set of "above-the-line" adjustments. It's one of the most important numbers on your tax return because so many other tax benefits are measured against it: the deductions you can take, the credits you qualify for, and the income thresholds where benefits phase out all key off your AGI (or a close cousin, MAGI). This calculator builds your AGI from your income and adjustments, and estimates your modified AGI too.
The formula
AGI = total income − above-the-line adjustments. Total income includes wages, interest, dividends, business profit, and other taxable income. Above-the-line adjustments are deductions you can take whether or not you itemize, including:
- Deductible traditional IRA and HSA contributions
- Student loan interest (up to $2,500)
- One-half of self-employment tax
- Self-employed health insurance and retirement contributions
- Educator expenses
Note that pre-tax 401(k) contributions are already excluded from your W-2 Box 1 wages, so you don't subtract them again here.
AGI vs. MAGI vs. taxable income
These three are easy to confuse:
- AGI — total income minus above-the-line adjustments.
- MAGI (modified AGI) — AGI with certain items added back (such as student loan interest or foreign income). It's used to test eligibility for Roth IRA contributions, the premium tax credit, and IRA deduction limits. MAGI's exact definition varies by benefit, so the figure here is a close approximation.
- Taxable income — AGI minus your standard or itemized deduction (and the QBI deduction). This is the number your tax brackets actually apply to.
Where to find last year's AGI
You often need your prior-year AGI to e-file — the IRS uses it to verify your identity when you submit a return electronically. You'll find it on last year's Form 1040, on the line labeled "Adjusted gross income" (it has been line 11 in recent years). If you don't have a copy of your return, you can pull your AGI from a free IRS tax transcript at irs.gov. Entering the wrong prior-year AGI is one of the most common reasons an e-filed return gets rejected, so it's worth confirming the exact figure rather than estimating it.
How to use your AGI
Once you know your AGI, you can check eligibility for credits and deductions in our 2026 tax credits and deductions guides, then estimate your actual tax with the full income tax calculator. If you're near a phase-out line, a last-minute above-the-line contribution before the filing deadline can be one of the most cost-effective tax moves available — lowering your AGI just enough to qualify for a credit you'd otherwise lose.