Check your tax bracket for 2012 by obtaining a copy of the Internal Revenue Service federal tax tables for that year, which is available from websites such as efile.com. Once you have obtained the tax table for 2012, find your tax bracket by using your net taxable income and your tax-filing status.
Most taxpayers pay taxes according to rates in several brackets, explains efile.com. When someone refers to your tax bracket, they are generally referring to the bracket in which the highest portion of income is taxed. This is also called the marginal tax rate. However, not the entire amount of the income is taxed at this rate. The lower portions of the income are taxed at lower rates, which is why the United States is said to have a progressive income tax system.
The combined rate a person pays for all the income brackets into which his income falls is known as the effective tax rate, adds efile.com. For example, in 2012, if a taxpayer filing as "single" reported $85,650 of taxable income, only the amount from $35,351 to $85,650 is taxed at the marginal tax rate of 25 percent. The other income falls into two lower tax brackets: from $1 to 8,700 is taxed at 10 percent, and from $8,701 to $35,350 taxed at 15 percent.