How Tax Brackets Work
A tax bracket is a band of income taxed at one rate. Each band is charged separately, so income fills the lower brackets before reaching the higher ones — the top rate you qualify for never applies to your whole income.
Brackets are slices, not categories
The most useful model is a stack of containers. Income fills the bottom container first, taxed at the lowest rate. When it is full, the overflow goes into the next one and is taxed at that rate. Nothing already in a lower container is re-taxed when the next one starts filling.
“Being in the 24% bracket” means the top of your stack has reached the 24% container. Most of your income is still sitting in the containers below it.
How to read a rate schedule
A published schedule gives a threshold and a rate. Read “24% on income over $105,700” as: every dollar above $105,700 costs 24 cents, and every dollar below it costs whatever its own band charges.
Some states publish the same thing as “base tax plus rate on the excess” — for example “$542.50 plus 3.5% of the amount over $35,000”. That is arithmetically identical; the base is the tax already accrued in the lower brackets, pre-calculated for you.
The thresholds are always taxable income, never gross income. Subtract the deduction first, or you will land in the wrong bracket.
Filing status changes the thresholds, not the rates
The same rates usually apply to every filing status; what changes is where each bracket starts. Married-filing-jointly thresholds are often, but not always, double the single ones. Head of household usually sits between the two.
Where a state publishes genuinely different schedules by status we publish all four — most sites publish only single and married filing jointly.