Your adjusted gross income (AGI) is your total income from all sources minus a specific list of subtractions the IRS calls “adjustments to income.” It is the single most consequential number on your tax return before the tax itself is figured. On Form 1040 it sits on line 11 — the line numbers in this article are from the 2025 Form 1040 and its Schedule 1, the current forms — and it is worked out before you take the standard deduction or itemize. Your AGI then acts as a gatekeeper: the IRS uses it to decide whether you qualify for many credits and other tax benefits, and you will be asked for last year’s AGI to prove your identity when you file electronically. The IRS’s own summary page is Adjusted gross income.
The formula fits in one line:
Total income − adjustments to income = AGI
Everything below is about what goes into those two terms — and what AGI is not, because it is routinely confused with taxable income and with its close relative, modified adjusted gross income (MAGI).
What counts as gross income
Gross income is all of your taxable income for the year, added together before anything is subtracted. The IRS definition of adjusted gross income lists the usual components: wages and salaries, tips, taxable interest, dividends, capital gains, business income, rental income, retirement income (pensions, annuities and taxable IRA withdrawals), and other taxable income such as unemployment compensation.
Two points in that list are worth slowing down on. First, capital gains are in — profit from selling stock, property or other assets is part of the income that builds your AGI (the rates themselves are a separate question: how capital gains tax works), and your AGI in turn is the starting point for several limits elsewhere on the return. Second, only taxable income counts. Money that the tax code excludes from income never enters the calculation at all, which is why your AGI is often noticeably lower than the total cash that passed through your life during the year even before adjustments.
Some income does not appear on the face of Form 1040 directly. Business income, rental and partnership income, farm income, unemployment compensation and a long “other income” list are first gathered in Part I of Schedule 1 and flow into your total income through line 8 of Form 1040. Keep Schedule 1 in mind: it is the same schedule whose Part II, described next, holds the adjustments that bring the total back down. Part I adds, Part II subtracts, and Form 1040 simply carries the results.
How to calculate AGI, following the form
Tax software does this arithmetic for you, but the form’s layout shows exactly what is happening, in three steps:
- Add up your total income. Every income item on the first page of Form 1040 is combined into total income on line 9.
- Add up your adjustments. Adjustments are listed on a separate schedule — Part II of Schedule 1, “Adjustments to Income.” Their total, on line 26 of Schedule 1, is carried to line 10 of Form 1040.
- Subtract. Line 9 minus line 10 gives line 11: your adjusted gross income.
That is the entire calculation. There is no percentage, no bracket and no rounding rule — AGI is simply what remains after a fixed list of subtractions has been taken from your total income.
A worked example
Suppose your year looks like this:
- Wages: $64,000
- Taxable interest: $800
- Income from a small side business: $5,200
Total income (line 9): $70,000
Now the adjustments that apply to you:
- Deductible contribution to a traditional IRA: $3,500
- Student loan interest paid: $900
- Educator expenses (you teach school): $300
Total adjustments (line 10): $4,700
$70,000 − $4,700 = $65,300. That $65,300 is your AGI — line 11. Note what has not happened yet: no standard deduction, no itemized deductions, no credits. All of those come later, and several of them will be measured against this $65,300 figure.
And if none of the adjustments apply to you — a common situation for someone whose only income is a salary, with no IRA contributions, student loan or self-employment — then there is no second term at all: your AGI simply equals your total income. A low or zero adjustment total is not a mistake; for many wage earners the two lines are legitimately identical.
The adjustments that lower AGI
Adjustments are a closed list — you cannot invent new ones, and they are the same for everyone, though only some will apply to you. Each one also carries its own eligibility rules and conditions, and several have a form of their own riding along (the HSA deduction arrives on Form 8889, the self-employment tax figure on Schedule SE, Armed Forces moving expenses on Form 3903). The table below is the map; the instructions for each line hold the fine print. They are often called “above-the-line” deductions because they are subtracted above the AGI line on the form, and unlike itemized deductions you claim them whether or not you itemize. Here are the main ones, with their lines on the 2025 Schedule 1 (Form 1040):
| Schedule 1 line | Adjustment | In plain terms |
|---|---|---|
| 11 | Educator expenses | Classroom costs paid by eligible teachers and other educators |
| 13 | Health savings account deduction | HSA contributions you make directly, reported on Form 8889 |
| 15 | Deductible part of self-employment tax | A portion of the self-employment tax self-employed people pay |
| 16 | Self-employed SEP, SIMPLE and qualified plans | Retirement contributions by self-employed people to their own plans |
| 17 | Self-employed health insurance deduction | Health insurance premiums paid by a self-employed person |
| 18 | Penalty on early withdrawal of savings | The penalty a bank kept when you cashed in a CD early |
| 19 | Alimony paid | Alimony paid under agreements the IRS still allows to be deducted |
| 20 | IRA deduction | Deductible contributions to a traditional IRA |
| 21 | Student loan interest deduction | Interest paid on a qualified student loan, up to $2,500 |
A few less common ones fill out the rest of Part II: moving expenses for members of the Armed Forces (line 14), certain business expenses of reservists, performing artists and fee-basis government officials (line 12), the Archer MSA deduction (line 23), and a short “other adjustments” list on line 24 that includes things like jury duty pay handed over to an employer.
One adjustment deserves a spotlight because it connects two parts of the tax code: if you contribute to an HSA yourself rather than through an employer’s payroll, that contribution appears here on line 13 — it is one of the few everyday moves that pulls AGI down directly. (What an HSA is and who can have one is its own question — see what is an HSA.) Everything else on the list is mostly a matter of recognizing what you already did during the year and reporting it on the right line.
How to lower your AGI
Read the table above backwards and you have the whole answer. AGI only falls when a genuine adjustment grows — a deductible traditional IRA contribution, an HSA contribution you make yourself, self-employed retirement contributions or health insurance premiums, student loan interest you actually paid. There is no other lever: the standard deduction cannot help, because it is subtracted after AGI is already set, and neither can a credit, which only reduces the tax at the end. For most wage earners with none of these in their year, AGI simply equals total income, and that is not a missed trick. It is just the shape of their return.
Where to find your AGI
For the return you are preparing now, your AGI is simply line 11 once the income section of Form 1040 is complete — the number does not exist until your income and adjustments are final.
For last year’s AGI, which is the one you are most often asked for, you have three routes, all described by the IRS on its adjusted gross income page:
- Your copy of last year’s return — line 11 of the Form 1040 you filed.
- Your IRS Online Account — sign in and select the tax year on the Records and Status tab.
- A free tax return transcript — request one from the IRS if you cannot log in or no longer have the return; the transcript shows the AGI from the return as filed.
Why does last year’s number matter so much? Because when you e-file, the IRS uses your prior-year AGI to confirm your identity — it is something only the person who filed that return should know. It is also the figure other programs reach for: the same AGI is used to qualify for free filing options, credits and other tax benefits. Keep the amount from the return as it was originally filed, and if you filed jointly last year, the AGI is the joint figure from that shared return, not a personal share of it.
Is your AGI on your W-2?
No — and this trips people up every filing season. Your W-2 comes from one employer and reports what that employer paid you. The box people mistake for AGI is Box 1, “Wages, Tips, Other Compensation”: one job’s taxable wages, and only one ingredient in the calculation. Your AGI cannot exist until every income source is added together and the adjustments are subtracted, and that arithmetic only happens on the tax return. That is why the number lives on line 11 of Form 1040 and nowhere else. Two jobs means two W-2s; interest, dividends, capital gains and side income sit on other forms entirely, and none of them knows about the others. Start with the W-2 by all means — just do not stop there and call the result your AGI.
AGI vs. taxable income
This is the confusion that matters most, so here it is plainly:
- AGI = total income − adjustments.
- Taxable income = AGI − the standard deduction or your itemized deductions, whichever you take.
Tax is charged on taxable income, not on AGI. The standard and itemized deductions are subtracted after AGI is set — that is exactly why the adjustments above are called “above the line”: they reduce your income earlier, and they do so regardless of which kind of deduction you take later. A dollar of adjustment lowers your AGI, and a lower AGI can also unlock or enlarge benefits that are phased out as AGI rises. A dollar of itemized deduction only helps if your itemized total beats the standard deduction. The two subtractions are not interchangeable, and calling adjustments “deductions” without that distinction — as many explainers do — hides the whole point of the AGI figure.
Credits are a third, separate stage that is also often folded into the same blur. A credit does not reduce your income at all; it reduces the tax computed on your taxable income, dollar for dollar, at the very end of the calculation. The full sequence on a return is therefore: total income, minus adjustments, gives AGI; AGI, minus the standard or itemized deduction, gives taxable income; tax is figured on taxable income; and credits then reduce that tax. AGI is the hinge in the middle of the sequence — early enough that almost everything after it is measured against it.
AGI vs. MAGI: the modified version
Modified adjusted gross income (MAGI) starts with your AGI and adds certain items back. There is no single MAGI: as the IRS explains on its modified adjusted gross income page, each tax benefit defines its own version, adding back whichever items that benefit cares about, and you calculate it separately for each benefit you are claiming.
The most common place you will meet MAGI is retirement accounts: for purposes of deducting a traditional IRA contribution, or contributing to a Roth IRA, MAGI adds back items such as your IRA deduction and student loan interest deduction — so you cannot use those very deductions to squeeze under the income limit they feed into. MAGI also decides eligibility for education credits, the premium tax credit for marketplace health insurance, and whether you owe the net investment income tax. For most people with simple finances, MAGI and AGI are the same number or very close; the gap appears only when you have the specific items a given benefit adds back.
The short version
AGI is total income minus a fixed list of adjustments, and it is fixed on line 11 of Form 1040 before any standard or itemized deduction is applied. It is not the amount you are taxed on — that is taxable income, one step further down — but it controls your access to a long list of credits and benefits, and last year’s AGI doubles as your identity proof when you e-file. If a form, a loan application or a benefits program asks for your income, the number it almost always wants is this one.
This article explains how adjusted gross income works in general. It is education, not personal tax advice — for a decision about your own return, check the IRS pages linked above or speak to a qualified tax professional.