Roth ladder planner: a ladder you can build in a browser, no power tools

By Tom, CPA · Updated October 25, 2026

TL;DR: Enter a yearly conversion amount, the number of years, other income and filing status. The planner estimates the federal income tax each conversion adds using 2026 brackets and standard deductions, and shows the year each conversion becomes penalty-free under the five-year rule.

Educational only, not tax, legal, or investment advice. Examples are illustrations, not predictions. Rules and limits change; verify current figures and talk to a qualified professional about your situation.

A Roth conversion ladder moves pre-tax money into a Roth IRA a little at a time, ideally in low-income early-retirement years, so that after five years each “rung” can be withdrawn without the 10% additional tax. This planner is a ladder you can build in a browser, no power tools: it shows the tax each rung adds and when you can climb it.

CPA Warning Label: Tax estimates use 2026 brackets for every year (future brackets will differ) and ignore state tax, credits, ACA subsidies and capital gains. Under 59½, each conversion has its own five-year clock starting January 1 of the conversion year.

Inputs

• Annual conversion: how much you’ll convert each year.
• Years: how many years you’ll convert.
• Start year: the first conversion year.
• Other income: other ordinary income each year, such as part-time work, interest or pension. (Qualified dividends and long-term gains are taxed differently and aren’t modeled.)
• Filing status: 1 for married filing jointly, 0 for single.

The defaults are an example: a married couple converting $40,000 a year for five years with $10,000 of other income.

Annual conversion schedule

The planner assumes the same conversion every year. In practice, many people vary it: convert more in a year with low income, less in a year with a big capital gain. Run it a few times with different amounts to see how the tax changes. A common target is to fill the standard deduction plus the 10% and 12% brackets: for 2026, that’s taxable income up to $100,800 for married filing jointly ($133,000 of gross ordinary income after the $32,200 standard deduction) or $50,400 single ($66,500 gross after $16,100).

Tax per year

The planner calculates tax on (other income + conversion) minus tax on other income alone, using 2026 brackets from Rev. Proc. 2025-32 and the 2026 standard deduction. That difference is the tax the conversion adds. For the example, about $1,780 a year, an effective 4.45% rate, because much of the conversion falls into the standard deduction and 10% bracket.

Larry converts $250,000 in one year and pays at 22% and 24%; Fran spreads it out and stays mostly in 10% and 12%. Same money in the Roth, very different tax bill.

Seasoning dates

Each conversion has its own five-year period for the 10% additional tax if you’re under 59½. The clock starts January 1 of the year you convert, so a conversion made any time in 2026 can be withdrawn penalty-free starting January 1, 2031. The planner shows the first and last rung’s dates. Converted amounts come out after regular contributions in the ordering rules, and earnings come out last.

You need other money for the five-year gap: a taxable account, Roth contributions, the Rule of 55 or a 72(t) plan.

How to use this calculator

1. Gather your numbers from statements and last year’s return; estimates are fine for a first pass.
2. Replace every example default with your own figure.
3. Change one input at a time to see which assumption moves the result most.
4. Save or screenshot the results with the date, since limits and rates change.
5. Bring the output to whoever prepares your return as a starting point, not a final answer.

What the planner leaves out

Conversions raise your modified AGI, which can reduce ACA premium tax credits, affect Medicare premiums two years later for people near 65, and change state tax. The planner estimates federal income tax only. If you rely on ACA coverage in early retirement, the subsidy effect can be larger than the tax itself, so check marketplace estimates at a few conversion amounts.

Reading the dates

The first and last accessible years mark the window when rungs become available. Each rung in between unlocks one year after the previous one. If you retire in 2026 and start converting right away, you need about five years of other spending money before the first rung unlocks in 2031, which is why taxable savings and Roth contributions matter.

Example

Illustration (calculator output): married, $40,000 per year for 2026–2030, $10,000 other income. Tax per year: about $1,780. Total converted: $200,000. Total federal tax: about $8,900. First rung available: 2031. Last rung available: 2035.

A single filer converting $30,000 a year for three years starting 2027 with no other income pays about $1,420 a year (2026 brackets), with rungs available 2032 through 2034.

See the early access guide and HSA as a retirement account for other bridge funds.