Free backdoor Roth IRA calculator. Estimate the tax cost of a backdoor Roth conversion including the pro-rata rule impact for 2025. See if backdoor Roth makes sense for high earners.
The Backdoor Roth IRA Calculator helps high-income earners who exceed the Roth IRA income limits use the backdoor strategy: contribute to a non-deductible Traditional IRA, then convert to Roth. For 2025, Roth IRA contributions phase out above $150,000 (single) or $236,000 (MFJ).
The biggest complication is the pro-rata rule. If you have any pre-tax money in Traditional, SEP, or SIMPLE IRAs, the IRS treats the conversion as coming proportionally from both pre-tax and after-tax funds — meaning you'll owe tax on a portion of the conversion even though your contribution was non-deductible.
Enter your IRA balances and contribution to see the tax impact and whether the backdoor Roth strategy is clean or complicated by the pro-rata rule. High earners who exceed the Roth IRA income limits can still contribute through the backdoor strategy, but pre-tax IRA balances create a tax trap that many overlook. This calculator quantifies the exact tax cost.
The backdoor Roth IRA is the only way for high earners to get money into a Roth IRA. This calculator quantifies the pro-rata rule tax impact, helping you decide whether to proceed with the conversion or first roll pre-tax IRA money into a 401(k) to avoid the pro-rata issue. This clarity is essential before executing the conversion to prevent unexpected tax consequences.
Total IRA Balance = Pre-Tax IRA + SEP IRA + SIMPLE IRA + Non-Deductible Contribution After-Tax Ratio = Non-Deductible Basis ÷ Total IRA Balance Taxable Portion = Conversion Amount × (1 − After-Tax Ratio) Tax Cost = Taxable Portion × Marginal Tax Rate
Result: Taxable: $6,140 | Tax: $1,965 | Tax-free: $860
With a $7,000 non-deductible contribution and $50,000 pre-tax IRA, the total IRA balance is $57,000. The after-tax ratio is $7,000/$57,000 = 12.3%. If converting $7,000, the taxable portion is $7,000 × 87.7% = $6,140, costing $1,965 in tax at 32%. Only $860 converts tax-free. The pro-rata rule makes this expensive.
The ideal scenario: you have zero pre-tax IRA balances (Traditional, SEP, and SIMPLE all at $0). You contribute $7,000 non-deductible to a Traditional IRA and convert to Roth immediately. The entire $7,000 moves to Roth with zero additional tax. Over 30 years at 7%, that grows to $53,248 — all tax-free.
If you have $100,000 in a Traditional IRA and contribute $7,000 non-deductible, your total IRA is $107,000 with only $7,000 (6.5%) being after-tax. Converting $7,000, only $457 is tax-free; the other $6,543 is taxable. This makes the backdoor Roth far less attractive. The solution: roll the $100,000 into your 401(k) first.
Many high earners do the backdoor Roth every year: contribute $7,000 in January, convert within a week, and invest the Roth. Over 20 years at $7,000/year, this creates a substantial Roth IRA — potentially $287,000+ at 7% returns — providing valuable tax diversification alongside their 401(k).
It's a two-step process for high earners who can't contribute directly to a Roth IRA: (1) Make a non-deductible contribution to a Traditional IRA, then (2) immediately convert that Traditional IRA to Roth. If you have no other pre-tax IRA balances, the conversion is virtually tax-free since you already paid tax on the contribution.
The IRS treats all your Traditional, SEP, and SIMPLE IRA accounts as one combined pool. When converting, the taxable and non-taxable portions are determined proportionally across the entire pool. You cannot choose to convert "only the after-tax money." This is why having pre-tax IRA balances complicates the backdoor Roth.
The cleanest approach is to roll all pre-tax Traditional, SEP, and SIMPLE IRA money into your employer's 401(k) plan before the conversion year ends. 401(k) balances are NOT counted for the pro-rata rule. With zero pre-tax IRA balance, the backdoor Roth convert is entirely tax-free.
Yes, the IRS has explicitly acknowledged this strategy. A proposed bill (Build Back Better Act) attempted to eliminate it in 2021 but did not pass. As of 2025, the backdoor Roth remains a legal and widely-used strategy. However, future legislation could change this.
Yes, most advisors recommend converting as soon as possible (within days) to minimize investment gains in the Traditional IRA, which would be taxable upon conversion. Some brokerages even offer automatic conversion features for this strategy.
You file Form 8606 with your tax return to report the non-deductible contribution and the Roth conversion. Part I reports the non-deductible contribution, Part II reports the conversion. Your broker will issue a 1099-R for the conversion. Keep Form 8606 records permanently.