How Is Federal Income Tax Calculated in 2026?
US federal income tax is progressive — different portions of your income are taxed at increasing rates from 10% to 37%.You don't pay your top rate on all your income. First subtract the standard deduction ($16,100 single / $32,200 married filing jointly for 2026) to get taxable income, then apply each bracket in turn. Only the dollars inside the top bracket you reach are taxed at that rate.
How to Use This Federal Tax Calculator
Enter your gross income, filing status, and any pre-tax adjustments (401(k), HSA, traditional IRA). Optionally add federal tax withheld to estimate your refund or balance due. The calculator returns your total tax, taxable income, and both your effective and marginal rates.
Effective vs Marginal Tax Rate
Your marginal rate is the bracket your last dollar falls in — it matters for decisions like a raise or an extra deduction. Your effective rate is total tax divided by total income, always lower because of the progressive brackets and standard deduction. A single filer earning $75,000 has a 22% marginal rate but only about a 10–12% effective rate. Explore the difference with our Effective Tax Rate Calculator.
Lower Your Federal Tax Bill Legally
Pre-tax contributions are the simplest lever: every dollar into a 401(k), HSA, or traditional IRA reduces taxable income at your marginal rate. Self-employed? Layer in the QBI deduction and business write-offs via our Self-Employment Tax Calculator. This tool covers federal income tax only — add FICA and your state's tax for a full picture.