In many states, the tax rate you pay escalates with increasing income. As you earn more, you progress into higher brackets, and the income in those brackets is taxed at a higher rate. This taxation approach is called progressive taxation,  and it’s designed to tax individuals proportionately to their earnings. In theory, the objective is for lower-income earners to pay a lower tax rate, while higher-income earners pay a higher tax rate.

This map illustrates the highest possible individual income tax rate someone might pay for the last dollar they make in a year. Note: That’s also likely to be higher than their effective tax rate (the average tax rate). 

Of course, some states also have no individual state income tax, and others have a flat tax.