The first thing you should do is use a tax estimator, here is a good one to use: https://turbotax.intuit.com/tax-tools/calculators/w4/ You can also read all about how to estimate your withholding here: https://turbotax.intuit.com/tax-tips/irs-tax-forms/how-to-estimate-federal-withholding/L99CO0yTK . Once you have used these links, contact them to submit a new W-4 to them. If you do not do it this way you will probably have a large tax bill to pay with your tax return and can even incur penalties and interest so please be careful with your withholding.
