Basis topic
Learn how after-tax basis can reduce the taxable portion of a Roth conversion and why recordkeeping matters.
The prefilled calculator example uses $40,000 of basis and $200,000 of traditional IRA balance to demonstrate how basis can affect a taxable conversion estimate.
After-tax basis is money in a traditional IRA that has already been taxed and may reduce the taxable portion of a Roth conversion.
The calculator uses basis and total traditional IRA balance to estimate the taxable conversion amount in a simplified educational model.
Accurate basis records, often associated with Form 8606, are important because poor records can make the estimate misleading.
Open the calculator with basis and IRA balance example assumptions prefilled, then replace them with verified records before relying on the output.
Open the calculatorThis educational page explains basis concepts only and does not provide tax, financial, legal, or investment advice.
This Roth Conversion Calculator is for educational and illustrative purposes only. It does NOT constitute tax, financial, legal, or investment advice. The calculation results are based on the information you provide and the latest IRS tax rules, which are subject to change. We do not guarantee the accuracy of the results. Please consult a licensed Certified Public Accountant (CPA), financial advisor, or tax professional before making any financial decisions.