How this calculator's numbers relate to your actual paycheck.
Does the OBBBA deduction change my per-paycheck withholding?
Not by default. The deduction is claimed annually on Schedule 1-A of Form 1040, reducing your federal tax bill at filing time. Your per-paycheck federal withholding stays the same unless you submit a new W-4. The IRS released a 2026 Form W-4 with a Section 1b worksheet allowing you to adjust withholding for the OBBBA deduction if you want the cash flow benefit during the year instead of at refund time.
Why doesn't this calculator include state taxes?
State income tax rules vary significantly by state — different rates, brackets, deductions, local taxes. Including state taxes would either require a full 50-state implementation or generic assumptions that could mislead you. For accuracy, this calculator shows federal income tax and FICA only. Your state withholding is separate, varies by state, and is not reduced by OBBBA in 43 states. See our
State Tax Guide.
How is federal withholding calculated?
The IRS percentage method (Pub. 15-T Worksheet 1A): annualize gross pay × pay periods per year, subtract standard deduction for your filing status, apply 2025 brackets, subtract $2,000 per dependent (Child Tax Credit), then divide annual tax by pay periods. This matches most employer payroll systems. Your actual W-4 may include more nuanced inputs (extra withholding, multiple jobs adjustment) not modeled here.
Why is my actual paycheck different?
Several reasons: pre-tax deductions (401(k), health insurance, HSA, FSA) reduce your taxable wages and are not modeled here; state and local taxes apply on top of federal/FICA; your W-4 may have extra withholding amounts entered; and your overtime hours often vary pay-to-pay. This calculator gives you the federal + FICA picture only.
Does FICA apply to my overtime pay?
Yes. Social Security (6.2% up to the wage base) and Medicare (1.45%, plus 0.9% Additional Medicare Tax over $200,000) apply in full to all overtime pay — including the premium portion deductible under OBBBA. The deduction reduces federal income tax only.
What about my tips? Should those be included?
Not in this calculator. Tip income has its own separate OBBBA deduction (up to $25,000 under IRC §224) and its own calculation — try our
Tips Calculator if you receive tips. If you want to model overtime AND tips together, use both calculators separately and add the savings.