Let me be sure I understand this. Per Michael Bomar's recent letter to the editor, it is incorrect to compare the taxes you will actually pay in 2018 to the taxes you actually paid in 2017. The correct methodology is to compare what you will actually pay in 2018 to what you didn't pay in 2017. That makes sense. I'm sure the IRS will be just fine with your using the 2018 rules and brackets when you prepare your 2017 return.
If you don't itemize deductions, here's a good estimate of what will happen in actual 2018 versus actual 2017. If you're single with income between $30,000 and $60,000, your tax is going down 20 percent or more. After $60,000, that steadily decreases to 15 percent at $100,000 and 9 percent at $200,000.
If you're married with no dependent children, the 20 percent or better reduction lasts up to $120,000 before tapering off. That same couple with one child will experience 30 percent or more through $80,000 and 20 percent up to $180,000. Add in a second child, and 30 percent lasts until $120,000 and 20 percent until $220,000.
If you itemize deductions, it can be a very different story. You'll need to use an online calculator to estimate your 2018 tax. I would suggest waiting until your 2017 return has been completed. Then you can compare your 2018 estimate to to your actual 2017 return, or you can opt to contrast it to the meaningless data Mr. Bomar advocates.
Corvallis (Jan. 11)