Marginal vs Effective Tax Rate

A worked example

Suppose a state charges 2% on the first $10,000 of taxable income, 5% on the next $40,000, and 8% above that, with a $5,000 standard deduction.

On $100,000 of income you subtract the $5,000 deduction, leaving $95,000 taxable. You pay 2% on the first $10,000 ($200), 5% on the next $40,000 ($2,000), and 8% on the remaining $45,000 ($3,600). Total: $5,800.

Your marginal rate is 8% — what the next dollar costs. Your effective rate is $5,800 ÷ $100,000 = 5.8%. Someone assuming the 8% headline rate applied to everything would have expected an $8,000 bill and been wrong by $2,200.

Why the confusion is expensive

“A raise will push me into a higher bracket and I’ll take home less” is the most common version of this mistake, and it is not how brackets work anywhere in the United States. Only the income above the threshold is taxed at the higher rate, so a raise always leaves you with more after tax.

The genuine cliff edges are elsewhere: means-tested benefits, insurance subsidies and some credits phase out abruptly at specific income levels. Those are real, and they have nothing to do with tax brackets.

Which one to use

Use the marginal rate for decisions at the edge — whether to take on extra work, make a deductible retirement contribution, or realise a capital gain this year rather than next. Those choices affect your last dollars.

Use the effective rate to compare places or years. It is the only number that answers “what share of what I earn goes to this tax”, which is what you want when comparing two states.

Every state page on this site shows both, at seven income levels.