Thanks to you and @Kat for taking a second look at this. Yes - future estimated taxes, as in 1040ES. While your method @rjs will work it's not very user friendly as you said. While digging into this issue I discovered that the IRS has its own Estimated Tax calculator Tax Withholding Estimator that seems to work pretty well. It's downside is that it doesn't differentiate qualified dividends or long term capital gains.
Is there a suggestion box for TurboTax where I could give the developers feedback?
