The new withholding calculator - expected out in late February - will assist individuals with more complicated situations to fine-tune their withholding calculations, he explained.
Workers with pass-through income from a small business or LLC can also expect to submit lower tax payments to the IRS.
Some businesses have already responded to those anticipated changes by granting bonuses and wage increases and by making or planning for additional investments.
For example, "the tables aren't created to account for married couples with two incomes, or side jobs with no withholdings", said Kathy Pickering, executive director of The Tax Institute at H&R Block.
Mr. Mnuchin added that about 76% of taxpayers typically see withholding amounts that result in refunds at the end of the year, and he doesn't expect that percentage to change under the new tables. Individuals, too, will soon see the benefits of tax reform by taking home bigger paychecks.