Estimating your income tax return comes down to two calculations: figuring out how much tax you owe for the year, then comparing that number to how much you’ve already paid through withholding or estimated payments. The difference is either your refund or your balance due. You can do this with a calculator, a spreadsheet, or the free IRS Tax Withholding Estimator, and the whole process takes about 15 minutes once you have your pay stubs handy.
Start With Your Gross Income
Your gross income is everything you earned during the year before any deductions. For most people, this means wages from a job, but it also includes freelance income, interest, dividends, rental income, retirement distributions, and unemployment benefits. If you’re estimating mid-year, take your year-to-date earnings from your most recent pay stub and project them forward. For example, if you’ve earned $30,000 through June, you can roughly double that for an annual estimate of $60,000.
If you have income from multiple sources, add them all together. Self-employment income counts as the net amount after business expenses. Investment income, side gigs, and any 1099 payments all go into this total.
Subtract Adjustments to Get Your AGI
Certain expenses reduce your income before the standard deduction even comes into play. These are called “above-the-line” adjustments, and they lower your adjusted gross income (AGI). Common ones include contributions to a traditional IRA, student loan interest (up to $2,500), health savings account contributions, and the deductible half of self-employment tax. If none of these apply to you, your AGI is the same as your gross income.
Your AGI matters because it determines eligibility for many credits and deductions. Write this number down; you’ll use it in the next step.
Apply the Standard Deduction
Most taxpayers take the standard deduction rather than itemizing. For the 2026 tax year, the standard deduction amounts are:
- Single: $16,100
- Married filing jointly: $32,200
- Head of household: $24,150
- Married filing separately: $16,100
Subtract the standard deduction from your AGI to get your taxable income. If you pay significant mortgage interest, state and local taxes, or charitable donations that together exceed your standard deduction, itemizing could lower your taxable income further. For this estimate, use whichever number is larger.
Calculate Your Tax Using the Brackets
Federal income tax uses a marginal system, meaning different portions of your income are taxed at different rates. You don’t pay one flat rate on everything. Each “bracket” applies only to the dollars that fall within its range.
Here’s how the 2026 brackets work for a single filer:
- 10% on the first $12,400
- 12% on income from $12,401 to $50,400
- 22% on income from $50,401 to $105,700
- 24% on income from $105,701 to $201,775
- 32% on income from $201,776 to $256,225
- 35% on income from $256,226 to $640,600
- 37% on income above $640,600
For married couples filing jointly, the brackets are roughly double: the 10% bracket covers the first $24,800, the 12% bracket runs to $100,800, and so on up to 37% on income above $768,700.
Let’s walk through a concrete example. Say you’re a single filer with $65,000 in taxable income. Your tax would be: 10% on the first $12,400 ($1,240), plus 12% on the next $38,000 ($4,560), plus 22% on the remaining $14,600 ($3,212). That totals $9,012 in federal income tax. Notice that even though part of your income falls in the 22% bracket, your overall effective rate is about 13.9%.
Subtract Credits You Qualify For
Tax credits reduce your tax bill dollar for dollar, which makes them more valuable than deductions. The most common credits for individuals and families include:
The Child Tax Credit is worth up to $2,200 per qualifying child for 2026. You get the full credit if your income is under $200,000 as a single filer or $400,000 filing jointly. Above those thresholds, the credit phases out gradually. If you owe little or no federal tax, you may still receive up to $1,700 per child as the refundable Additional Child Tax Credit, as long as you have at least $2,500 in earned income.
The Earned Income Tax Credit benefits lower and moderate-income workers. The amount depends on your income, filing status, and number of children. A family with three or more qualifying children can receive several thousand dollars, while workers without children qualify for a smaller credit. The EITC is fully refundable, meaning it can generate a refund even if you owe zero tax.
Other credits to check include the education credits (American Opportunity and Lifetime Learning), the child and dependent care credit, and energy-related home improvement credits. Subtract any credits you qualify for from the tax figure you calculated in the previous step. The result is your total tax liability for the year.
Compare Your Tax to What You’ve Already Paid
This is where your estimate turns into a refund or a balance due. Pull out your most recent pay stub and look at the “federal tax withheld” line. If it shows year-to-date withholding, project that to a full-year amount. For instance, if $4,800 has been withheld through eight months, your estimated annual withholding would be around $7,200.
If you also made quarterly estimated tax payments (common for freelancers and self-employed workers), add those to your withholding total. The sum of all payments made throughout the year is what you compare against your total tax liability.
If you’ve paid more than you owe, the difference is your refund. If you’ve paid less, you’ll owe the balance when you file. Using the example above, if your tax liability is $9,012 and your total withholding is $10,500, you’d get roughly a $1,488 refund.
Use the IRS Tax Withholding Estimator
If you’d rather not do the math by hand, the IRS offers a free online tool called the Tax Withholding Estimator at irs.gov. It walks you through the same steps and handles the bracket calculations automatically. To use it, you’ll need your most recent pay stubs (and your spouse’s, if filing jointly), records of any self-employment or gig income, and information about deductions or credits you plan to claim.
The tool gives you an estimated refund or balance due and can also suggest how to adjust your W-4 at work if your withholding is too high or too low. Running it once or twice a year, especially after a major life change like a new job, marriage, or a new child, helps you avoid surprises at tax time.
Quick-Reference Estimation Worksheet
Here’s the process condensed into a simple sequence you can follow on paper or in a spreadsheet:
- Step 1: Add up all income sources for the year (wages, freelance, investments, etc.)
- Step 2: Subtract above-the-line adjustments (IRA contributions, student loan interest, HSA contributions) to get your AGI
- Step 3: Subtract the standard deduction (or your itemized total if it’s higher) to get taxable income
- Step 4: Apply the tax brackets to your taxable income to calculate your raw tax
- Step 5: Subtract any tax credits (Child Tax Credit, EITC, education credits) to get your total tax liability
- Step 6: Add up all federal withholding and estimated payments you’ve made
- Step 7: Subtract your tax liability from your total payments. A positive number is your estimated refund; a negative number is what you’ll owe.
Keep in mind this estimate covers federal income tax only. State income taxes follow their own brackets and rules, so your total tax picture may look different depending on where you live. Your estimate also won’t be perfectly precise until you have final year-end numbers, but getting within a few hundred dollars is realistic with accurate pay stub data and a clear picture of your deductions and credits.