Roth IRA Conversion Calculator

Last updated July 2, 2026

A Roth IRA conversion moves money from a traditional IRA or 401(k) into a Roth account, triggering income tax on the converted amount in the year of conversion but eliminating all future taxes on that money's growth and withdrawal. The strategic case for conversion is strongest during years when income is unusually low relative to expected future income — the gap between retirement and age 73 when RMDs begin is the classic conversion window, when a retiree may be in the 12 or 22 percent bracket temporarily before RMDs push them into the 24 or 32 percent bracket for decades.

The conversion calculator models the break-even point: how many years of tax-free Roth growth does it take to recoup the taxes paid on conversion? For a $50,000 conversion taxed at 22 percent, the immediate tax cost is $11,000. If the converted amount grows at 7 percent in the Roth account versus 7 percent net of taxes in the traditional account (where future withdrawals would be taxed), the break-even is approximately 7 to 10 years depending on future tax rates. The break-even shortens when future tax rates are expected to be higher than the conversion rate — either because income will be higher, tax law may shift, or RMDs will force large taxable distributions. It extends when future rates will be similar to or lower than today's conversion rate.

Modeling a partial Roth conversion in years where your income temporarily drops or where you can fill the 22 or 24 percent bracket cheaply — staying below thresholds that would trigger higher Medicare premiums or Social Security taxability is part of the analysis. Convert strategically rather than all at once, watching the tax bracket ceiling and the Medicare IRMAA thresholds as guardrails. The conversion calculator makes the break-even year visible so you can evaluate whether the tax bill today is worth the tax freedom later.