Roth Conversion Calculator

Roth conversion makes the most financial sense when your current tax rate is lower than your expected future tax rate. The ideal conversion window is typically between retirement and age 73 — after earned income has dropped but before RMDs begin forcing taxable withdrawals. During this window, you can convert amounts that keep your taxable income in the 12% or 22% bracket, paying taxes now at a lower rate to avoid higher taxes later. It also makes sense when you want to reduce future RMDs, leave tax-free assets to heirs, or diversify your tax exposure in retirement.

A backdoor Roth conversion is a two-step process for high earners who exceed the Roth IRA income limits. In 2026, direct Roth IRA contributions are phased out between $153,000 and $168,000 for single filers and between $242,000 and $252,000 for married filing jointly. High earners above these thresholds make a nondeductible contribution to a Traditional IRA and then immediately convert it to a Roth IRA. Because the contribution was made with after-tax dollars, there is little or no additional tax owed on the conversion itself. The backdoor Roth has no income limit — anyone can do it.

The pro-rata rule applies when you have a mix of pre-tax and after-tax money in your Traditional IRA. If you attempt a backdoor Roth conversion but have existing pre-tax IRA funds, the IRS treats all your IRA assets as a single pool for tax purposes. The taxable percentage of your conversion is calculated proportionally across all your IRA assets — not just the non-deductible portion. For example, if you have $90,000 in pre-tax IRA funds and make a $10,000 nondeductible contribution, 90% of any conversion is taxable. The pro-rata rule can significantly complicate backdoor Roth strategies when large pre-tax IRA balances exist.

The optimal annual Roth conversion amount is typically the amount that fills your current tax bracket without pushing income into the next bracket. For a single filer in the 22% bracket in 2026, that means converting enough to bring total taxable income up to $103,350 — the top of the 22% bracket — without crossing into 24%. Converting a predictable amount each year in the years between retirement and age 73 creates a systematic tax-efficient ladder that reduces the Traditional IRA balance subject to future RMDs. A financial advisor or CPA can model the optimal annual conversion amount for your specific situation.

Yes — they are treated differently by the IRS. Roth IRA contributions have income limits ($153,000–$168,000 single, $242,000–$252,000 married in 2026) and must come from earned income. Roth conversions have no income limits and no earned income requirement — anyone with a Traditional IRA can convert at any time. The five-year holding rule also differs: each conversion has its own five-year clock for penalty-free withdrawal of converted principal, while Roth IRA earnings require a five-year account age plus age 59½ for penalty-free withdrawal.

Roth IRA assets are exempt from RMDs during the owner's lifetime. Every dollar successfully converted from a Traditional IRA to a Roth IRA is permanently removed from future RMD calculations. This means lower taxable income in retirement, potentially lower Medicare premiums (which are income-based under IRMAA), and tax-free growth for heirs. For retirees with large Traditional IRA balances facing significant future RMDs, a systematic Roth conversion strategy in the years before age 73 can meaningfully reduce lifetime tax liability.