January 28, 2020 You can use the Tax Withholding Estimator to estimate your 2020 income tax and decide if you need to change your withholding with your employer. If you have questions while using the estimator or about your results, check out the frequently asked questions. The FAQs cover a variety of topics including: Where to enter information How to account for certain deductions and adjustments How to qualify for certain credits Understanding your results