Tax Rates

The chart below shows the bracket changes that will take effect in 2018 as described in Title I of the 2017 tax act. For comparison, it's followed by a chart showing 2017 rates and the changes that were slated to take effect in 2018 absent passage of the tax bill.
The 2017 tax act also makes the following income tax adjustments for 2018:
The deduction for personal exemptions, which had been $4,050 for 2017, is suspended.
The standard deduction for single taxpayers and married taxpayers filing separately rises to $12,000 from $6,350.
The standard deduction for married taxpayers filing joint returns rises to $24,000 from $12,700.
The standard deduction for heads of household rises to $18,000 from $9,350.

The chart below shows the bracket changes that were slated to tax effect without passage of the Tax Cuts and Jobs Act:
Revenue Procedure 2017-58, now superseded by the Tax Cuts and Jobs Act, also stated that among other income tax adjustments for 2018:
The personal exemption would have risen by $100 to $4,150 from $4,050.
The standard deduction for single taxpayers and married taxpayers filing separately would have risen by $150 to $6,500 from $6,350.
The standard deduction for married taxpayers filing joint returns would have risen by $300 to $13,000 from $12,700.
The standard deduction for heads of household would have risen by $150 to $9,550from $9,350.