A flat tax rate applies the same percentage to everyone’s taxable income, while a progressive tax charges higher rates as income rises. In simple terms: flat tax is one rate for all; progressive tax has brackets, so higher earners pay a larger share.

Quick difference

Feature| Flat tax| Progressive tax
---|---|---
Rate structure| One rate for all income levels 35| Multiple rates that rise with income 35
How tax grows| Tax owed rises only because income rises, not because the rate changes 3| Tax owed rises faster for higher incomes because the rate increases in brackets 5
Typical use| Common in some state income taxes and in taxes like sales/payroll taxes 35| Used by the U.S. federal income tax system 5

Simple example

If a flat tax is 15%, someone earning 30,000 and someone earning 300,000 both pay 15% of their taxable income. Under a progressive system, the lower earner pays lower brackets first, and the higher earner eventually hits higher brackets like 22%, 24%, 32%, or more depending on income.

In plain language

Flat tax is easier to understand because the rate stays the same. Progressive tax is designed so people with higher incomes contribute a larger percentage of their income, which is why it is often described as more “ability-to-pay” based.

If you want, I can also give you a 1-minute explanation with a real paycheck example.