Roth Conversion Calculator

Roth conversions, in plain English

A Roth conversion moves money from a traditional IRA or pre-tax 401(k) into a Roth IRA. You voluntarily pay ordinary income tax on the converted amount this year, and in exchange every dollar in that Roth grows tax-free forever. Qualified withdrawals after age 59.5 come out with zero federal income tax, and there are no Required Minimum Distributions on Roth IRAs during your lifetime.

The core math

The decision comes down to one question: is your tax rate today lower than the rate you would pay on that money in the future? If yes, converting usually wins. If you are in a 22% bracket today but expect to be in 24% or 32% later (because RMDs, Social Security, and a paid-off house push your income up), paying tax at 22% now is a bargain. This calculator shows the break-even future tax rate so you can see how much your assumption has to change to flip the answer.

Why "low-income years" matter

The best conversion opportunities are usually the gap years after you retire and before Social Security and RMDs kick in. Say you retire at 62 and delay Social Security until 70. Between 62 and 72, your taxable income might be very low. Filling up the 12% and 22% brackets with conversions during those years can save six figures over a retirement.

Pay the tax from outside funds

If you have to withhold the tax from the IRA itself, you shrink the amount that lands in the Roth. If you can write a check from taxable savings to cover the tax bill, every dollar of the conversion keeps growing tax-free. Toggle the option in the calculator to see how much that decision matters over time.

Watch the ripple effects

A large conversion is income. It can push you into a higher bracket, add to the taxable portion of your Social Security, and trigger IRMAA surcharges on Medicare Part B and D two years later. It can also affect ACA subsidies if you are pre-Medicare. Most people convert in slices, filling a target bracket without spilling into the next one.

The five year rule

Each conversion has its own five year clock for penalty-free access to the converted amount if you are under 59.5. Once you are past 59.5 and have had any Roth IRA open at least five years, this becomes a non-issue for most people. If you are converting close to retirement, factor it in.

How to think about the answer

Do not treat the winner in this calculator as gospel. Nobody knows future tax rates or future returns. Use the tool to answer a more useful question: how confident are you that your future rate will be higher than the break-even rate shown? If the break-even is way above what you realistically expect, converting is a strong move. If it is close to your best guess, converting is a coin flip and worth splitting across several years.