> Please just add it up and send me the bill. I don't want to pay more than what's due. And I don't want to cheat.

I have a hard time understanding this comment because this is exactly what employers do when paying out RSUs.

At the end of the year, you get a 1099 indicating the fair market value of shares you've received. There's no trickery here--this is literally the amount you owe income tax on.

I'm not sure what tax software you're using that requires you to guess inputs and numbers. TurboTax makes this trivially straightforward.