Roth Conversion Calculator
Estimate the tax on a conversion and the room left in your federal bracket. Compare converting now with leaving the money in a traditional IRA.
For a single filer with $120,000 of other income, a $100,000 conversion adds about $29,134 in modeled tax: $24,134 federal plus $5,000 state.
The effective rate climbs as the conversion grows
| Converted | Federal tax | Effective rate | Top bracket reached |
|---|---|---|---|
| $25,000 | $5,964 | 23.9% | 24% |
| $50,000 | $11,964 | 23.9% | 24% |
| $100,000 | $24,134 | 24.1% | 32% |
| $200,000 | $57,564 | 28.8% | 35% |
| $400,000 | $127,564 | 31.9% | 35% |
How to use the estimate
Start with a conversion whose tax bill you could pay without draining needed cash. Test smaller amounts and compare them with spreading conversions across years. Staying within a bracket can reduce this year’s bill, but future tax rates and other income determine the longer-term tradeoff.
The growth comparison assumes qualified Roth withdrawals and a constant return. When tax comes from outside savings, the traditional-IRA alternative includes a side investment with 15% tax on its modeled capital gain. Future tax rates and investment results can change which option finishes ahead.