You said you're trying to calculate how much estimated tax to pay in January. Instead of trying to do all the complicated calculations now, it would be much simpler and easier to wait until the TurboTax software for 2024 is available. You can then use TurboTax to do a preliminary calculation of your 2024 tax. The preliminary desktop TurboTax software will be available for download in mid to late November, and TurboTax Online will be available in early December. That still gives you plenty of time to calculate how much to pay in January.
