As of 2014, individuals and married couples filing the tax form 1040A use the Federal 1040A tax table to determine the amount of taxes owed based on income, says the Internal Revenue Service. The taxpayer determines the amount of taxable income before using the table.
The person uses his income from line 27 and finds the amount under the headings At Least and But Less Than column. After finding the correct line, the taxpayer selects the amount of taxes owed on that line based on his filing status such as single, married filing separately, married filing jointly and head of household, according to the IRS. The taxpayer enters the tax amount on line 28.