Backdoor Roth IRA Calculator
Calculate the tax impact of a backdoor Roth IRA conversion including the pro-rata rule if you have existing pre-tax IRA funds.
What Is a Backdoor Roth IRA? High earners above the Roth IRA income limits ($161,000 single / $240,000 married in 2024) cannot contribute directly to a Roth IRA. The backdoor strategy is a legal workaround: contribute to a traditional IRA (non-deductible), then immediately convert it to a Roth.
The Pro-Rata Rule — The Catch If you have ANY other pre-tax IRA money (rollover IRA, deductible IRA, SEP IRA, SIMPLE IRA), the IRS requires you to treat your entire IRA portfolio as one pot. You cannot pick and choose which dollars you convert.
Pro-Rata Formula Taxable % = Pre-tax balance ÷ (Pre-tax balance + All non-deductible basis) Tax owed = Conversion amount × Taxable % × Marginal tax rate
Clean Backdoor (Best Case) If you have zero pre-tax IRA balance, the conversion is 100% tax-free. This is the “clean” backdoor — the ideal scenario.
Example with Pro-Rata You contribute $7,000 non-deductible. But you also have $63,000 in a rollover IRA. Total IRA assets = $70,000. Pre-tax = $63,000. Taxable % = $63,000 / $70,000 = 90%. Tax on $7,000 conversion = $7,000 × 90% × 32% = $2,016.
Solution: Roll It Out If your employer plan accepts incoming rollovers, move the pre-tax IRA balance there first. Then do the backdoor conversion with zero pre-tax IRA balance.