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Roth Conversion Room Calculator

2026 brackets and Medicare tiers · reviewed September 4, 2026

Shows how much you can move from a traditional IRA to a Roth this year before the tax rate steps up or Medicare premiums rise. About

In plain words. A Roth conversion moves money from a pre-tax retirement account to a Roth account, and you pay income tax on the amount moved that year. Tax rates go up in steps called brackets, and Medicare premiums go up in steps called tiers. This tool takes your income and shows how much room is left in your current bracket and before the next Medicare tier, and what a conversion of any size would cost.

Why it matters. A conversion sized to the room costs the current rate; one that runs past it costs the next rate on the excess, and can raise Medicare premiums two years later. The room is the number to convert to, not past.

An example. A single person with $100,000 of income has about $21,800 of room in the 22 percent bracket. Converting $30,000 costs about $6,800 in tax, because the last $8,200 is taxed at 24 percent.

Where it stops. It assumes the standard deduction and ordinary income only. Capital gains, dividends, and a Social Security benefit that becomes more taxable as income rises all shrink the room, so a conversion is sized with your actual return in hand. Everything it leaves out.

$

Your total income before deductions, line 11 of Form 1040. Leave out the conversion you are planning.

Filing status

Your taxable income before converting is $83,900, after the $16,100 standard deduction.

Room left in your 22% bracket
$21,800
You can add that much more ordinary income before your rate goes up. The next dollar past it is taxed at 24%. Your Medicare premium tier stays where it is unless your income rises by $9,000 or more.
Federal tax brackets for a single filer in 2026, with your income and the conversionA horizontal bar of the single brackets up to $212k. Taxable income before converting fills $83,900. The conversion adds $25,000, reaching $108,900. Dashed marks show where the Medicare premium tiers fall on the same scale.10%12%22%24%32%Medicare tier $93kTier 2 $121kTier 3 $155kTier 4 $189k
Federal tax added by the conversion
$5,564
22.3% of the $25,000 converted
Your tax bracket after converting
24%
On $108,900 of taxable income
Change in Medicare premiums in 2028
+$1,148
Per year, moving from tier 0 to tier 1

The first $21,800 converts at 22%. The rest climbs into the 24% bracket. Medicare sets your premiums two years later using this year's adjusted gross income, so the 2026 return sets 2028 premiums. The tiers are cliffs. One dollar over a line costs the whole step up. The same rule links the 2024 return to 2026 premiums.

This uses the 2026 federal brackets the IRS published in Rev. Proc. 2025-32, the standard deduction, and the Medicare premium tiers. It treats all income as ordinary income. It leaves out capital gains, the 3.8 percent investment surtax, state tax, itemized deductions, the extra deduction for people 65 and older, and the effect on how much of your Social Security is taxed. Each of those can change the room, which is why a conversion is best planned with a tax return in hand. Educational, not advice.

This is a simplified model, not your actual tax return or plan. It only knows what you type in, leaves out rules that may apply to you, and cannot weigh the other facts and trade-offs a real decision depends on. Before you act, talk with a professional who knows your whole situation.

Educational only, not investment, tax, or legal advice. Results are hypothetical estimates that vary with each use and over time and are not guaranteed accurate or complete. Using this tool creates no client relationship with Considerate Capital, and the site that linked here is not affiliated with it. By using it you agree to the tool terms.