Figuring out estimated taxes a year ahead of time doesn't do me much good. I might have no capital gains for the year if I don't sell securities or I might have a few hundred thousand, but I have no idea at the beginning of the year what I might sell. I might have an idea of what dividends I might get throughout the year, and could keep track of charitable contributions and other income, but I really need a tool to do this throughout the year as things happen.
In addition to knowing what my quarterly payments should be based on actual income (I'd still have an issue if I have a subsequent quarter where I sell securities at a huge loss) there are other things I'd want to figure out such as how much I could use from an IRA to make a Roth conversion without increasing my income to the point that my tax bracket goes up and my Medicare premiums go up.
I could wait until the end of the year, hope that Turbotax comes out with enough time for me to cram the numbers in to estimate, but is there a better way? I'd need to do this before making end of year decisions, so January would be too late.
