How much of my backdoor Roth conversion is taxable in 2025?
Check how the pro-rata rule affects a backdoor Roth conversion for 2025 or 2026. Enter after-tax IRA contributions, existing basis, pre-tax IRA balances, and planned conversion amount to estimate the taxable and tax-free portions of the conversion and remaining basis.
How this calculation works
- Adds after-tax contributions and existing basis to calculate total basis.
- Uses the pro-rata formula based on total IRA balances.
- Estimates taxable versus tax-free conversion amounts.
Common mistakes and caveats
- SEP, SIMPLE, and rollover IRAs are included in the pro-rata calculation.
- Year-end IRA balances can change the final taxable portion.
- This estimate does not calculate additional taxes beyond the conversion.
FAQ
Do pre-tax IRA balances affect backdoor Roth taxes?
Yes. The pro-rata rule includes all pre-tax IRA balances when determining the taxable portion.
Last updated & sources
Last updated January 27, 2026.
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