If you use this tool and/or are more familiar with taxes than I am, please have a look and let me know if I should make any adjustments.
I appreciate your help.
Happy New Year!
P.S. To pull in the 2021 tax rates, just update your template using the Tiller Money Labs add-on. Be aware that you will need to reenter the manual-entry fields for income & expense adjustments, home office adjustments, and business mileage.