There are two types of income tax rates: (1) regular rates, which apply to all taxpayers, and (2) alternative minimum tax (AMT) rates, which apply only if certain tax benefits, when added back to your income, result in an AMT tax that exceeds your regular tax.
Most taxpayers do not have to compute the regular tax. They find the tax for their income and filing status in the IRS Tax Table if their taxable income is less than $100,000 (22.2). The Tax Computation Worksheet must be used to figure your regular income tax if taxable income is $100,000 or more (22.3). However, if you have net capital gain or qualified dividends, do not use the Tax Table or the Tax Computation Worksheet. Instead, figure your regular tax liability on the applicable capital gains worksheet in the IRS instructions (22.4). Use the Foreign Earned Income Tax Worksheet to figure your regular tax if you are claiming the foreign earned income exclusion or foreign housing exclusion (22.5).
To determine if you owe alternative minimum tax (23.1), you have to complete Form 6251.