How the math works
We apply the 2025 federal tax brackets against your taxable income (gross minus 401(k) minus the federal standard deduction), then your state's brackets against state taxable income, and add FICA (6.2% Social Security up to the wage base of $176,100, plus 1.45% Medicare on all wages, plus an extra 0.9% on wages above $200,000).
What it does not model
This estimator covers federal income tax, state income tax, and FICA. It does not include local/city taxes (NYC, Yonkers, Philadelphia, Ohio cities, Maryland counties, etc.), pre-tax health insurance, HSA contributions, post-tax deductions, tax credits (CTC, EITC), or itemized deductions. For exact withholding, use your employer's payroll system or a CPA.