Short term capital gains will be taxed as ordinary income.
Long-term capital gains rates can be found in the link: 2025 Long-Term Capital Gains Tax Rates (for filing in 2026)
Add the amount you plan to withdraw from your traditional IRA to your other sources of income (without long-term capital gains) to produce gross income. If you are filing single, subtract the 2025 standard deduction of $15,750 from the amount you calculated to determine your estimated taxable income.
Compare your figure to the table in the link above. This should allow you to estimate an amount you can convert from your traditional IRA to a Roth IRA before you move up into the 15% Long-Term capital gain bracket.
This assumes you have no gains from sales that apply to the collectibles rate.
