What Is a Roth Conversion? A Plain-English Guide

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By The Money Floor Editorial Team · Source-verified · Last updated August 2026

A Roth conversion is when you move money from a traditional IRA or old 401k — where you haven’t paid taxes on it yet — into a Roth IRA, where it will grow tax-free for the rest of your life. You pay income tax on the amount you convert in the year you do it. That’s the whole thing. You’re essentially paying your tax bill now, on your terms, so you never have to pay taxes on that money again. For people who think they’ll be in a higher tax bracket later (or just want to stop worrying about future tax bills), this move can be genuinely powerful. The IRS confirms that Roth conversions are available to anyone regardless of income — unlike direct Roth IRA contributions, which have income limits.

Why a Roth Conversion Matters (Especially If You Feel Behind)

Here’s the honest reason this matters if you’re 35, 40, or 45 and feel like you’re playing catch-up: you may have decades of tax-free growth sitting untouched in a traditional IRA or an old 401k from a previous job. That money is growing, yes. But when you pull it out in retirement, every dollar gets taxed as ordinary income. If tax rates go up between now and then (and the long-term trend hasn’t been reassuring), you’ll pay even more.

A Roth conversion lets you lock in your tax rate today. If you’re in a relatively low tax bracket right now — maybe your income dipped this year, you took time off, you changed jobs, or you’re in between careers — converting some of that pre-tax money can be a genuinely smart move. You pay taxes at today’s lower rate instead of a potentially higher rate in retirement.

Roth IRAs also have no required minimum distributions (RMDs) during your lifetime. Traditional IRAs force you to start withdrawing at age 73, whether you need the money or not. A Roth just sits there, growing, until you want it. That flexibility alone makes the conversion worth understanding.

And if you’re already thinking about a Roth IRA but your income is too high to contribute directly, a Roth conversion (sometimes called a “backdoor Roth”) is the legal workaround that higher earners use every year.

How a Roth Conversion Actually Works

Think of it like this: your traditional IRA is a gift that’s still wrapped. The government let you skip paying taxes when you put that money in, but they’re keeping a receipt. When you retire and start unwrapping it, they’ll tax every dollar. A Roth conversion is you saying, “I’d rather pay for the wrapping paper now, so everything inside is mine forever.”

Here’s what actually happens mechanically:

1. You contact your brokerage (Fidelity, Vanguard, Schwab, wherever your account lives) and request a Roth conversion. This can often be done online in under 10 minutes.
2. They move the money from your traditional IRA to your Roth IRA. If you don’t have a Roth IRA yet, you open one at the same time.
3. The converted amount gets added to your taxable income for that year. Convert $10,000 and your income effectively goes up by $10,000 for tax purposes.
4. You pay taxes on that amount when you file your return. Your brokerage sends you a Form 1099-R in January showing the conversion.
5. The money is now in your Roth IRA, growing tax-free. Future withdrawals in retirement — including all the growth — are completely tax-free, as long as you follow the basic rules.

A real example: Say you have $30,000 in a traditional IRA. You decide to convert $10,000 this year. You’re in the 22% federal tax bracket. That conversion adds $10,000 to your taxable income, and you’ll owe roughly $2,200 in federal taxes on it. The remaining $20,000 in the traditional IRA stays put. You can convert more next year, or the year after — there’s no deadline to do it all at once.

The key rule: pay those conversion taxes with money from outside the IRA, not from the converted amount itself. If you pull money from the IRA to cover the tax bill, you’ve just reduced the amount growing tax-free, and if you’re under 59½, part of that withdrawal could trigger a 10% penalty on top of the taxes. Pay the tax from your checking account or savings. Always.

How to Get Started Today

You don’t need a financial advisor to do a basic Roth conversion. Here’s the step-by-step for a beginner:

1. Check your current year’s tax bracket. Look at your most recent pay stub or last year’s tax return. The IRS publishes current brackets at irs.gov. You want to know how much room you have before hitting the next bracket up.
2. Calculate how much you can convert without jumping a bracket. If you’re single and your taxable income this year is $40,000, you have $5,000 of room before hitting the 22% bracket threshold. You could convert $5,000 and stay in the 12% bracket. That’s a 12% tax rate on money that will now grow tax-free forever.
3. Log into your brokerage account. Look for an option like “Convert to Roth” or “Roth conversion” in the IRA section. Fidelity and Vanguard both have this in their account management tools. If you can’t find it, call them — it usually takes one phone call and 15 minutes.
4. Choose how much to convert. Start conservative. Converting $3,000 to $10,000 in your first year is completely fine. You can convert more next year.
5. Set aside money to cover the tax bill. If you convert $10,000 and you’re in the 22% bracket, set aside at least $2,200 in a separate savings account before you file your taxes. Don’t get caught flat-footed in April.
6. Report it on your tax return. Your brokerage handles the paperwork (Form 1099-R). Your tax software (TurboTax, FreeTaxUSA, etc.) will walk you through entering it. The process is straightforward.

If you’re also doing gig work or have variable income, timing your conversion to a lower-income year matters even more. Our guide on gig work and quarterly taxes has context on how your total income picture affects your bracket.

Common Mistakes Beginners Make With Roth Conversions

Getting this wrong doesn’t ruin you. But it costs real money. Here are the mistakes worth knowing before you start.

Converting too much in one year

This is the big one. If you convert $50,000 in a single year without checking your brackets first, you could push yourself from the 22% bracket into the 24% or even 32% bracket. The extra taxes on that top chunk wipe out a lot of the long-term benefit. Convert in smaller amounts across multiple years instead. Slow and steady works perfectly well here.

Using IRA funds to pay the tax bill

Covered above, but worth repeating: never cover the conversion taxes by pulling more from the IRA. Pay from outside money. If you don’t have outside money to cover the taxes, that’s a signal you’re converting more than you can afford right now.

Ignoring state income taxes

Federal isn’t the only tax on conversions. Most states also treat the converted amount as taxable income. If you live in a high-tax state, factor that in. A $10,000 conversion might cost $2,200 federally plus another $500 to $900 in state taxes depending on where you live.

Converting right before a big income year

If you know you’re getting a promotion, a large bonus, or selling an investment next year, wait. Do the conversion in the lower-income year, not the higher one. Timing matters more than speed.

Forgetting about the five-year rule

Roth IRA earnings have a five-year rule: you need to have had a Roth IRA open for at least five years before you can withdraw earnings tax-free (even after age 59½). The clock starts January 1 of the year you first opened or contributed to any Roth IRA. If you’re 40 and you convert today, your Roth earnings are tax-free at 45. That’s still decades before most people retire. But if you opened your first Roth at 58, you’d need to wait until 63 to touch earnings penalty-free. Start the clock as soon as possible. You can check how this interacts with late-start investing strategies in our guide on starting a Roth IRA at 40.

According to Investopedia, each conversion amount you roll in actually has its own separate five-year clock for penalty purposes on the converted principal — though the earnings clock runs from the original Roth IRA opening date. It’s a nuance that matters most if you’re under 59½ and think you might need the money soon. If you’re planning to leave the money alone until retirement, it almost never comes up.

Frequently Asked Questions

What is a Roth conversion in simple terms?

A Roth conversion is when you move money from a traditional IRA or 401k — where taxes haven’t been paid yet — into a Roth IRA, where it will grow and be withdrawn tax-free. You pay income tax on the amount you convert in the year you do it. After that, the money is yours, tax-free, forever.

Is there an income limit on Roth conversions?

No. Anyone can do a Roth conversion regardless of income. This is different from contributing directly to a Roth IRA, which phases out for single filers earning above $150,000 and joint filers above $236,000 in 2026. Conversions have no income cap, which is why high earners often use them as a backdoor strategy.

How much does a Roth conversion cost in taxes?

The converted amount gets added to your taxable income for the year, and you pay your regular income tax rate on it. If you convert $10,000 and you’re in the 22% federal tax bracket, you’ll owe roughly $2,200 in federal taxes on that conversion. State income taxes may also apply depending on where you live.

Can I convert just part of my traditional IRA?

Yes, absolutely. You can convert any amount you choose — $1,000, $5,000, $25,000, or all of it. Most people convert in smaller annual amounts to avoid jumping into a higher tax bracket. There’s no rule saying you have to convert everything at once.

What’s the difference between a Roth conversion and a backdoor Roth IRA?

A backdoor Roth IRA is a specific type of Roth conversion used by high earners who can’t contribute directly to a Roth IRA due to income limits. The process: you contribute to a traditional IRA (which has no income limit for contributions), then immediately convert that money to a Roth IRA. The mechanics are the same as any Roth conversion — the “backdoor” just refers to the two-step workaround for high earners.

Should I do a Roth conversion if I’m in my 40s and behind on savings?

It depends on your current tax bracket and whether you have money outside the IRA to pay the conversion taxes. If you’re in a low-income year or the 12% bracket, even converting $5,000 to $10,000 can be a smart move. Don’t convert if you’d need to pull from the IRA itself to pay the taxes. Our catch-up savings guide for your 40s has more on prioritizing when you’re behind.