Roth Conversion Calculator

A Roth IRA conversion is a transfer of funds from a Traditional IRA (or a qualified employer plan) into a Roth IRA. The converted amount is treated as taxable income in the year of the conversion. The benefit is that future growth and withdrawals from the Roth IRA are tax-free, provided the 5-year rule and age requirements are met. This calculator estimates the immediate tax cost so you can evaluate whether the long-term tax-free benefit is worthwhile.

The pro-rata rule requires that all Traditional IRA balances be treated as a single pool for tax purposes when converting. If you have both pre-tax (deductible) and after-tax (non-deductible) contributions, the IRS does not allow you to convert only the after-tax portion tax-free. Instead, every dollar you convert is taxed proportionally. For example, if 70% of your total Traditional IRA balance is pre-tax, then 70% of any conversion is taxable income. This calculator applies the pro-rata rule automatically.

The most common strategy is to roll your pre-tax IRA balance into a workplace 401(k) or 403(b) plan before doing the conversion. Most employer plans accept rollovers from IRAs and are not counted in the pro-rata calculation. After moving the pre-tax dollars out, only after-tax basis remains in the IRA, and the entire remaining amount can be converted tax-free. Check your plan's summary plan description or call your provider to confirm they accept IRA rollovers.

Spreading a conversion over multiple years can be tax-efficient because it limits the amount of income pushed into higher tax brackets each year. For example, converting $200,000 all at once might push $150,000 into the 32% bracket, but spreading it over 4 years at $50,000 per year might keep all the taxable income within the 22-24% bracket. This calculator's multi-year mode helps you compare both approaches. The downside of spreading is that you lose tax-free growth on the unconverted balance during the waiting years.

No, this calculator only models federal income tax. State income tax rates vary from 0% (no-income-tax states like Florida, Texas, Nevada) to over 13% (California). State tax can add a significant cost to a conversion and should be considered separately. If your state has no income tax, the federal-only estimate is fairly complete.

If you are converting now, use 2025. If you are planning for late 2026 or want to see the impact of potential TCJA expiration, use 2026. The 2026 brackets are projections based on the Tax Cuts and Jobs Act individual provisions sun-setting at the end of 2025 and may change with future legislation. Converting at today's lower rates (2025) before the brackets potentially increase in 2026 is a common strategic consideration.

Other income includes your gross wages, business income, interest, dividends, capital gains, rental income, pension distributions, Social Security benefits (taxable portion), and any other items that appear on your Form 1040. The calculator uses this figure to determine which marginal tax bracket your conversion income falls into. For the most accurate bracket placement, use your projected Adjusted Gross Income (AGI) minus any IRA conversion amounts.

Multi-year mode divides your total conversion amount equally across the number of years you specify. Each year, the calculator recalculates the pro-rata ratio using the remaining pre-tax and after-tax balances, then computes the tax on that year's conversion using that year's brackets. Because the after-tax basis is consumed first proportionally, early years in a multi-year spread may have a slightly different taxable ratio than later years.