How this calculator works
The estimator computes your AGI as wages + other ordinary income + LTCG/qualified dividends − pre-tax contributions. It then subtracts either the $32,200 MFJ standard deduction or your itemized deductions (whichever is larger) to get taxable income.
Tax is computed in two layers. First, ordinary taxable income (everything except LTCG and qualified dividends) runs through the 2026 MFJ ordinary brackets. Second, LTCG and qualified dividends are stacked on top of ordinary taxable income — the LTCG bracket thresholds ($0–$98,900 at 0%, $98,900–$613,700 at 15%, $613,700+ at 20%) are based on total taxable income, not LTCG alone, so ordinary income "uses up" some of the lower LTCG brackets first.
Finally, the Child Tax Credit ($2,200 per qualifying child, phased out by $50 per $1,000 above $400,000 AGI) is subtracted, capped at the total tax owed.
What's not included
- Net Investment Income Tax (3.8%) on investment income above $250,000 AGI
- Additional Medicare Tax (0.9%) on wages above $250,000
- Self-employment tax (15.3% on SE income up to the Social Security wage base)
- Qualified Business Income (QBI) deduction for pass-through business income
- Alternative Minimum Tax (AMT)
- Education credits (American Opportunity, Lifetime Learning)
- Saver's Credit, EITC, Premium Tax Credit, Adoption Credit, etc.
- State and local income taxes
- FICA (Social Security + Medicare withholding) — these are payroll taxes, not income tax, and are separate from what this calculator estimates
Frequently asked questions
What is this calculator estimating exactly?
Your total federal income tax liability for the 2026 tax year, filing as Married Filing Jointly. It applies the 2026 MFJ brackets to ordinary income, stacks long-term capital gains and qualified dividends on top at the preferential 0%/15%/20% rates, and subtracts the Child Tax Credit. If you provide your year-to-date federal withholding, it also estimates whether you will get a refund or owe a balance.
Why do long-term capital gains and qualified dividends use different brackets?
Long-term capital gains (assets held more than a year) and qualified dividends are taxed at preferential rates — 0%, 15%, or 20% — instead of ordinary income rates. They "stack" on top of your ordinary taxable income: ordinary income fills the lower LTCG brackets first, then your gains and qualified dividends fall into whichever LTCG brackets remain. For 2026 MFJ, the 0% rate covers total taxable income up to $98,900 and the 15% rate covers up to $613,700.
Should I enter pre-tax 401(k) contributions in the wages field or the contributions field?
Use the wages field for your gross wages (before any pre-tax deductions). Then enter your annual 401(k), traditional IRA (if deductible), HSA, and similar pre-tax contributions in the dedicated field. The calculator subtracts them to compute AGI. If your W-2 box 1 already excludes these, you can enter the box 1 amount as wages and leave the contributions field blank — but be careful not to double-count.
How accurate is this for tax planning?
For a wage-earning couple with straightforward investment income, the result should be within a couple hundred dollars of your actual return. Accuracy degrades for: self-employment income, rental income, pass-through business income with QBI deduction, large itemized deductions with phaseouts, AMT-triggering situations, and households subject to the Net Investment Income Tax or Additional Medicare Tax. Use this as a starting point, not a substitute for tax software or a CPA.
Why does the marginal rate shown differ from what I expected?
The "marginal rate" is the rate that would apply to your next dollar of ordinary income — it is determined by where your taxable income lands in the bracket structure, not by your total income. Couples are often surprised that a $200,000 combined-income household sits in the 22% bracket (after the standard deduction takes them well below the top of the $100,800–$211,400 2026 22% range).