Deorbit Plan

Roth conversion tax calculator (2026)

The federal tax a conversion adds this year, and the brackets it fills

By the Deorbit Plan editorial team, a Berrydyne program · Last reviewed · Topic: Roth conversions

What it computes

A Roth conversion is taxed as ordinary income in the year you convert[1]. This calculator stacks the conversion on top of your other ordinary income, runs the 2026 federal brackets and standard deduction for your filing status[3] twice (with and without the conversion), and reports the difference: the extra federal tax, the effective rate on the converted dollars, the top bracket reached and the room left in it.

Roth conversion tax calculator (2026 brackets)

  • Federal tax without the conversion: $2,840. With it: $8,840.
  • Extra federal tax from converting: $6,000. An effective rate of 12% on the converted dollars. Once the conversion spans more than one bracket, this differs from your marginal rate.
  • Top bracket reached: 12%. $23,000 of room left before the next bracket starts.
  • The entire $50,000 conversion lands in the 12% bracket.
Standard deductionOther income12% bracketConversion starts$0$25K$50K$75K$100K
How $60,000 of other income and a $50,000 conversion fill the Married filing jointly 2026 brackets. Dollar amounts on the bar are GROSS income (the standard deduction, $32,200, is shown as its own segment). The bracket boundaries quoted elsewhere on this page are in taxable income.

Federal ordinary income tax only. State tax, NIIT, the effect on Social Security taxation and capital-gains stacking are left out. See “What this calculator ignores” below.

Worked example

A married couple filing jointly with $60,000 of other income owes $2,840 of federal tax. Converting $50,000 raises that to $8,840: $6,000 more, an effective 12% on the converted dollars, all inside the 12% bracket with $23,000 of room left before the next one.

Convert $100,000 instead and the extra tax is $14,700, or 14.7% effective, because the conversion now spans $73,000 at 12% and $27,000 at 22%. The marginal rate on the last dollar (22%) and the effective rate on the whole conversion are different numbers; the second is what the conversion costs.

Filing status used: Married filing jointly. No ages are entered, so no age-65 or senior deduction applies.

What it ignores

  • State income tax.
  • How the conversion makes more Social Security taxable, pushes capital gains out of the 0% band, or triggers the net investment income tax. The marginal-rate map and the simulator show those interactions.
  • The age-65 additional standard deduction and the temporary senior deduction.
  • Medicare IRMAA two years later and ACA premium credits, each keyed to its own version of modified adjusted gross income.
  • The five-year clock on withdrawing converted principal before 59½[2], and estimated-tax safe harbors[4].

The rule behind it

The full explanation, with sources, is in Roth conversion tax calculator (2026).

See it over a full plan

One year rarely tells the story. The simulator runs a multi-year "fill the bracket" conversion plan across your own income path, with RMDs, IRMAA and taxes included. Open it in the simulator →

If you already have a saved plan, the link only takes you to the right panel; your plan is not changed.

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This tool shows how the rules work. It is not financial, tax or investment advice. See the disclaimer.

Sources