Roth Conversion Window Calculator
Convert traditional IRA dollars to Roth now, convert partially, or wait? This engine compares the future after-tax value of converting against leaving the money in a traditional IRA — and flags the two costly mistakes.
Your decision
Convert partially. Converting $50,000 costs about $13,500 in tax now and would be worth $119,828 tax-free in 15 years — versus $91,069 after tax if left in the traditional IRA.
Recommendation
GoodConvert partially
Driven by the gap between your current and retirement tax brackets, and whether you can pay the tax from cash.
Tax due on conversion
Watch$13,500
at 27.00% combined
Federal + state on the converted amount, owed this year.
Future Roth value
Good$119,828
tax-free
Grows and is withdrawn tax-free in retirement.
Net advantage vs traditional
Good$28,759
Future Roth value minus the after-tax value of leaving it in the traditional IRA.
Ranked options
#1Convert partially
Fill the top of your current bracket without spilling into the next one or crossing an IRMAA threshold.
Confidence: MediumEffort: LowRisk: Low#2Convert now (full amount)
Locks in today's 22.00% rate; best when your retirement bracket will be higher and you can pay the tax from cash.
Confidence: MediumEffort: LowRisk: Medium#3Wait
Better if your bracket will be lower in retirement, or if you cannot pay the tax from outside cash.
Confidence: MediumEffort: LowRisk: Low
Watch-outs
- • Estimates use a single flat bracket and ignore bracket-by-bracket fill. This is not tax advice — confirm with a tax professional, especially near IRMAA or ACA thresholds.
Assumptions used
- Conversion amount
- $50,000
- Current bracket
- 22.00%
- Retirement bracket
- 24.00%
- Years to retirement
- 15
- Expected return
- 6.00%
- Pay tax from
- Outside cash
Estimates based on your assumptions above — roughly indicative, not financial, tax, or legal advice.
Why this matters
A Roth conversion is a tax bet: pay tax now at your current rate to avoid it later. It wins when your retirement bracket will be higher and you can pay the tax from outside cash. It backfires when you pay the tax out of the IRA itself or convert so much you jump a bracket or cross a Medicare IRMAA threshold.
Frequently asked questions
This tool produces estimates based on the assumptions you enter. It is not financial, tax, or legal advice. Actual rates, fees, and outcomes depend on your lender, account terms, and approval.