If you are a W-2 employee, the IRS Withholding Calculator can help you determine whether you need to give your employer a new Form W-4, Employee’s Withholding Allowance Certificate to avoid having too much or too little Federal income tax withheld from your pay.

The IRS tool will also help you fill out the W-4, but cautions that it may not work perfectly for all taxpayers and that you should contact a Tax Professional before changing your withholding.