Federal Tax Estimator

Your marginal rate is the rate on your last dollar of income — the top bracket you fall into. Your effective rate is what you actually pay as a percentage of total income, which is always lower because each bracket only applies to income within that range. For example, a single filer with $100,000 of taxable income has a 22% marginal rate but an ~16% effective federal rate.

Yes — traditional 401(k) contributions are pre-tax. They reduce your Adjusted Gross Income (AGI), lowering both your federal tax and potentially moving you into a lower bracket. Contributing $10,000 to a 401(k) at a 22% marginal rate saves ~$2,200 in federal taxes. Roth 401(k) contributions do NOT reduce current taxes — they're made with after-tax dollars but grow tax-free.

FICA (Federal Insurance Contributions Act) funds Social Security (6.2% up to $168,600 in 2024) and Medicare (1.45% on all wages, plus 0.9% on earnings over $200,000 for single filers). Unlike income tax, FICA applies to gross wages before any deductions. W-2 employees split this with their employer; self-employed individuals pay the full 15.3%.

Take whichever is larger. The 2024 standard deduction is $14,600 (single), $29,200 (married jointly), or $21,900 (head of household). You should itemize only if your qualifying expenses — mortgage interest, state/local taxes (capped at $10,000), charitable donations, and certain medical expenses — exceed your standard deduction. About 90% of filers take the standard deduction.