Hi, this is a very good question. You should 1st try to figure out how much in taxes you will actually owe. 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 . 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. Instead of paying estimated taxes on your Rover Income, you can ask your employer to withhold additional amounts from your W-2 income once you estimate how much your tax will be on your Rover income just break that amount up per your remaining paychecks to come up with the number of additional withholding to add to W-4.
