When preparing your annual tax return, you must eventually turn to the tax tables included in the 1040 instruction booklet. The tables offer a convenient way to look up the amount of tax you owe without having to go through a multipart calculation. Tax tables are also offered online through the Internal Revenue Service website, but if you're using tax software, you shouldn't need them at all.
DIY Tax Calculation
If you enjoy doing calculations, the calculation for figuring income tax is given in the 1040 instruction booklet and online under "Tax Computation Worksheet." As of 2015, the Internal Revenue Service imposed seven different tax brackets: 10, 15, 25, 28, 33, 35 and 39.6 percent of your taxable income. These are marginal rates, which apply to specific levels of income; your "tax rate" is actually the percentage applied to your last dollar of income. This depends, in turn, on your filing status: single, married filing a joint return, married filing a separate return and head of household.
Tabling the Matter
Instead of using a calculator or a sheet of paper, you can simply rely on the IRS tax tables, which have done the calculation for you. Using the tax table, which you've found in the 1040 instruction booklet or online, and find the line that shows your taxable income, which should appear on line 43 of your tax return. This is your income after deductions, exemptions and any other adjustments -- but before tax credits are applied.
Go to Line 44
Follow the line across to the four filing status categories on the right side of the table. Your tax appears under the correct filing status for your return. Enter this number on line 44 of the return. Your credits and any other adjustments to tax will be added or subtracted in the lines to follow.
Waiting Till Next Year
Tax tables can be useful for estimating the amount of tax you will owe next year. If you expect to make more money, look up this amount and then file a new W-4 form to adjust income tax withholding from your wages. If you own a business or are self-employed and you expect your income to change, prepare to adjust your quarterly estimated tax payments.