IRS Withholding Calculator
The IRS Withholding Calculator has been adjusted to account for the Tax Reform and Jobs Act. Due to significant changes resulting from the new tax law, taxpayers who are wage-earners should use the calculator to determine whether they need to update their withholding. This may be particularly important for taxpayers with a significant balance due or a larger than normal refund for tax year 2018.
If the taxpayer is a wage-earning employee, the Withholding Calculator helps them determine whether they need to give their employer a new Form W-4, Employee's Withholding Allowance Certificate, so that the proper amount of withholding can be withheld from their pay check. The calculator mirrors the Form W-4 worksheet. The taxpayer can use the results from the calculator to help fill out the form and adjust their income tax withholding.
The calculator's results will only be as accurate as the information provided by the taxpayer. During the year if the taxpayer's circumstances change (Examples: job change, marital status change, have a child), they will need to use the calculator to ensure their withholding is still correct.
Whereas the Withholding Calculator works for most taxpayers, those with more complex tax situations should use the instructions in Publication 505, Tax Withholding and Estimated Tax.