Effective tax rate calculator

Effective versus marginal tax rate

Two numbers describe your taxes, and people constantly confuse them. Your marginal rate is the rate on your next dollar - the bracket you are in. Your effective rate is your total federal tax divided by your total income - the blended average across all the brackets your income passes through. The effective rate is always lower, and the gap surprises people who think being “in the 24% bracket” means paying 24% on everything.

Worked example

A single filer earning $200,000, taking the standard deduction:

• Taxable income: $200,000 − $16,100 = $183,900
• Federal income tax: about $36,734
• Marginal bracket: 24% (income lands in the 24% band)
• Effective rate: $36,734 ÷ $200,000 = about 18.4%
• After-tax income: roughly $163,266

So this taxpayer is “in the 24% bracket” but actually pays about 18.4% of income in federal tax - a six-point difference that matters for every planning decision.

Why the gap exists

The US federal system is progressive. Your first ~$12,400 is taxed at 10%, the next chunk at 12%, then 22%, then 24%, and so on. Only the income above each threshold is taxed at the higher rate. Stack those layers together and the average comes out well below the top rate.

Why this matters

• Roth conversions and extra income are taxed at your marginal rate, not your effective rate - so use the marginal number when deciding whether to take on more taxable income.
• Comparing job offers or retirement scenarios is best done with the effective rate, which reflects your real tax burden.
• “Moving into a higher bracket” never lowers your take-home pay - only the income above the threshold is taxed more.

What this leaves out

This calculator shows federal income tax only. Your true all-in rate is higher once you add:

• FICA (7.65% on wages up to the Social Security cap, plus the 0.9% Medicare surtax for high earners),
• State income tax, which ranges from zero to over 13%.

Common mistakes

• Believing your whole income is taxed at your top bracket.
• Using the effective rate to judge the cost of one extra dollar (use marginal).
• Forgetting state and payroll taxes when comparing total burden.

To size the marginal cost of adding income, see the Roth conversion calculator; for quarterly planning on untaxed income, see the estimated tax calculator.