One of the quiet perks of retiring early is how little tax you can end up paying. The federal system is genuinely kind to people living off investments with modest incomes. Then a few states show up and undo most of it. Here's how the pieces fit, and how the calculator runs the real numbers.
When you sell an investment you've held longer than a year, the profit is a long-term capital gain, and the federal government taxes it at lower rates than a paycheck: 0% or 15% for most people, versus the 10% to 37% ordinary brackets that apply to wages. Qualified stock dividends get the same favorable treatment. For someone retired early and living off a brokerage account, that's the whole ballgame, and it's why selling shares to fund your life is so much cheaper than it sounds.
The 0% rate isn't a rounding error. In 2026 it runs up to about $49,450 of taxable income for a single filer and $98,900 for a married couple filing jointly. And that's after the standard deduction, which is $16,100 single and $32,200 joint this year. Stack those together and, if capital gains are your only income, you can realize somewhere around $65,550 as a single filer or $131,100 as a couple and owe the IRS nothing on those gains.
Order matters here, and the calculator follows the real rules. Your ordinary income (mostly 401k or traditional IRA withdrawals) gets counted first, and the standard deduction comes off of that. Then your long-term capital gains stack on top. So if you pull from a traditional account, that income fills up the lower brackets and pushes your gains higher in the stack, where more of them can spill into the 15% range. Spend purely from a brokerage and you stay in capital-gains land the whole way. The tool computes the gross withdrawal you'd need, applies the deduction once, taxes 401k money as ordinary income, taxes brokerage gains at the capital-gains rates on top, and shows you what's actually left.
Here's where it gets uneven. Plenty of states either have no income tax or follow the federal capital-gains logic. A few don't, and they tax your long-term gains as plain old income with no break at all. The two that catch the most early retirees:
| State | How it treats long-term gains |
|---|---|
| California | Ordinary income, roughly 1%–12.3%. No capital-gains break. |
| New York | Ordinary income, roughly 3.9%–10.9%. No capital-gains break. |
| No-income-tax states | $0 on gains (Texas, Florida, Washington, and others). |
| Most other states | Vary; the calculator uses a flat estimate of about 5%. |
The practical upshot is blunt: where you live can swing the size of the portfolio you need to retire. The exact same plan that costs a Floridian nothing in gains tax can hand a Californian a five-figure annual bill, which means a bigger nest egg to net the same spending. I'm not telling anyone to move. But if you're flexible on geography, it's one of the few levers that genuinely moves your number.
If you're running a Roth conversion ladder, remember that each conversion is ordinary income for that year. That income fills the brackets first and eats into the room you had for 0% capital gains. There's a real balancing act between converting enough to build your ladder and not converting so much that you push your gains into the taxable range. The calculator accounts for the interaction so you can see the net effect rather than guess at it. Those conversions also lift your MAGI, which can shrink your ACA health-insurance subsidy, so the real trade-off is bigger than income tax alone.
See your after-tax retirement numberNot financial advice, and definitely not tax advice. State rules and brackets change; confirm specifics with a CPA or a fee-only fiduciary CFP. Tax figures use 2026 brackets.