If you’re curious about the effects of the new federal tax law (i.e., the reconciliation act of 2017, formerly known as the Tax Cuts and Jobs Act), I’ve created an on-line calculator that shows the impact of the new tax law by calculating the federal income tax under both the old law and the new law, taking into account not just the differences in rates but also the changes in deductions for medical expenses, state and local income taxes, mortgage interest, charitable contributions, and miscellaneous itemized deductions, as well as the elimination of the personal exemption and the increases in the standard deduction and the child credit.

A similar feature has been added to the income tax calculations for estates and trusts (although the differences are generally less significant).

See http://wcalcs.com (registration required).