Marginal vs. Effective Tax Rate
Nobody actually pays their tax bracket rate on their whole paycheck — the number people quote and the number they actually pay are two different things.
What Is It
Your marginal tax rate is the rate applied to your last dollar of income — the top bracket you reach. Your effective tax rate is your total tax divided by your total taxable income — the actual average rate you pay. The U.S. uses a progressive system: income is taxed in layers, with each bracket’s rate only applying to the slice of income that falls within that bracket, not your entire income.
Because of this layering, your effective rate is always lower than your marginal rate, for anyone earning above the lowest bracket — the two numbers describe genuinely different things, and neither one is “more correct” than the other. They’re just answering different questions: marginal tells you what happens to your next dollar, effective tells you what happened to all of them.
Why It Matters
The most common misconception this causes: people think moving into a higher bracket means their whole income gets taxed at that new, higher rate. It doesn’t — only the portion above the threshold does. This misconception leads to real bad decisions, like turning down a raise or a bonus out of a mistaken fear it’ll all get “taxed away.”
It’s also the reason marginal rate — not effective rate — is what actually matters when deciding whether to make a pre-tax 401(k) or Traditional IRA contribution: that contribution saves you tax at your marginal rate, on your top slice of income, since that’s the slice it’s effectively removing. The same logic runs in reverse for a Roth conversion: the income you add gets taxed starting at whatever bracket you’re currently sitting in, which is why converting a large amount in one year can push part of it into a materially higher marginal bracket than you’d expect from looking at your effective rate alone.
Quick Example
Single filer, $70,000 in taxable income. The first $12,400 is taxed at 10% ($1,240). The next $38,000, from $12,400 to $50,400, is taxed at 12% ($4,560). The remaining $19,600, from $50,400 to $70,000, is taxed at 22% ($4,312). Total tax: $10,112. Marginal rate: 22% — the rate on that last slice of income. Effective rate: $10,112 ÷ $70,000 = 14.45% — the actual average rate paid across the whole $70,000.
Try your own numbers: