A backdoor Roth IRA lets high earners contribute to a Roth IRA even when they exceed the direct contribution income limits. The strategy involves contributing to a non-deductible Traditional IRA and then converting to Roth — but the pro-rata rule may make part of the conversion taxable if you have other pre-tax IRA balances.
Step 1: Your IRA Balances (as of December 31, 2025)
Important: The pro-rata rule combines ALL pre-tax Traditional IRA, SEP IRA, and SIMPLE IRA balances held in your name. Your 401(k) and 403(b) are NOT included.
Existing deductible Traditional IRA balance
Counts toward pro-rata calculation
Max: $7,000 (under 50) or $8,000 (age 50+) for 2026
Pro-Rata Rule Calculation
Net Benefit Analysis
Strategies to Eliminate Pro-Rata Problem
How to Use the Backdoor Roth IRA Calculator
The backdoor Roth IRA strategy is a two-step workaround for high earners who exceed the Roth IRA income limits. This calculator handles the most complex part: determining how much of your conversion will be taxable based on the IRS pro-rata rule.
Step 1: Non-Deductible Traditional IRA Contribution
Contribute up to $7,000 (or $8,000 if age 50+) to a Traditional IRA. Since you exceed the income limits for Roth, you also likely exceed the limits for deducting Traditional IRA contributions — so this contribution is non-deductible (after-tax). You track this using Form 8606 when you file your taxes.
Step 2: Convert to Roth
Shortly after contributing, convert the Traditional IRA to a Roth IRA. If you had no other IRA balances and you convert immediately, the conversion is essentially tax-free (you already paid tax on the contribution). The tax complexity comes from the pro-rata rule.
The Pro-Rata Rule Explained
If you have existing pre-tax IRA balances (deductible Traditional IRA, SEP IRA, or SIMPLE IRA), the IRS treats all IRAs as one combined pool. The taxable percentage of any conversion equals: pre-tax IRA balance ÷ total IRA balance. For example, if you have $63,000 pre-tax and add $7,000 non-deductible ($70,000 total), then 90% of any conversion is taxable — even if you only convert the $7,000 you just contributed.
Clean Backdoor Roth (No Pro-Rata)
The cleanest backdoor Roth scenario: you have $0 in pre-tax IRA accounts before doing the strategy. Contribute $7,000 non-deductible, convert immediately — 0% is taxable, 100% goes tax-free to Roth. This is available to employees with pre-tax IRA money rolled into their 401(k) before year-end.
FAQ
Is this backdoor Roth calculator free?
Yes, completely free with no signup. All calculations run locally in your browser. Your financial data is never transmitted or stored.
What is a backdoor Roth IRA?
A backdoor Roth IRA is a two-step strategy used by high earners who earn too much to contribute directly to a Roth IRA. Step 1: Contribute to a Traditional IRA (non-deductible, after-tax). Step 2: Convert that Traditional IRA to a Roth IRA. The conversion is legal but the tax treatment depends on other IRA balances.
What is the pro-rata rule?
The pro-rata rule prevents you from only converting the non-deductible (after-tax) portion of your IRA. The IRS treats all your Traditional, SEP, and SIMPLE IRAs as one combined pool. The taxable portion of each conversion equals pre-tax IRA balance divided by total IRA balance. If you have $90,000 pre-tax and add $7,000 non-deductible, 93% of any conversion is taxable.
How do I avoid the pro-rata rule?
The most common strategy is to roll your pre-tax Traditional IRA balance into your employer 401(k) or 403(b) before doing the conversion. This removes the pre-tax IRA balance from the pro-rata calculation. Not all plans accept IRA rollovers — check with your employer. Another option is to convert all IRA balances to Roth and pay the full tax at once.
Does my 401(k) balance count in the pro-rata calculation?
No. Your 401(k), 403(b), and similar employer plans are not included in the pro-rata calculation. Only Traditional, SEP, and SIMPLE IRAs held in your name are included. This is why rolling pre-tax IRA money into your 401(k) effectively solves the pro-rata problem.
What tax form do I need for a backdoor Roth conversion?
You need Form 8606 to report non-deductible IRA contributions and conversions. Part I tracks non-deductible contributions and your IRA basis. Part II reports the taxable amount of any Roth conversions. File this with your annual tax return each year you make a non-deductible contribution or conversion.
Is my financial data private?
Absolutely. All calculations happen entirely in your browser. No data is sent to any server — your IRA balances, income, and tax information are never transmitted or stored.
What is IRA basis?
IRA basis is the total of all non-deductible (after-tax) contributions you have made to traditional IRAs over the years. This is tracked on Form 8606 each year you make a non-deductible contribution. Your basis is not taxed when withdrawn — only the pre-tax portion is. Keeping accurate records of your basis prevents double taxation.