Question: what is the percentage of federal income tax?
Answer: The U.S. currently has seven federal income tax brackets, with rates of 10%, 12%, 22%, 24%, 32%, 35% and 37%. If you're one of the lucky few to earn enough to fall into the 37% bracket, that doesn't mean that the entirety of your taxable income will be subject to a 37% tax. Instead, 37% is your top marginal tax rate.