How Does a Roth IRA Work, and How Does It Grow Over Time? (2024)

Traditional individual retirement accounts (IRAs) are known for their tax advantages. But how does a Roth IRA work—specifically, how does it grow over time? Your contributions help, but it’s the power of compounding that does the heavy lifting when it comes to building wealth with a Roth IRA.

Your account has two funding sources: contributions and earnings. The former is the most obvious source of growth, but the potential for dividends and the power of compounding can be even more important.

What Is a Roth IRA?

IRAs, both traditional and Roth, are popular savings vehicles among those who understand the importance of planning for retirement. It’s easy to open an account using an online broker or with the guidance of a financial planner.

The defining characteristic of a Roth IRA is the tax treatment of contributions. In a traditional IRA, contributions are made with pretax dollars, meaning that they reduce the amount of your taxable income when you make them; you pay income tax when you withdraw the funds later.

Conversely, contributions to Roth IRAs are made with after-tax dollars. There’s no tax break when you make them, but any contributions that you make are yours to withdraw tax-free at your discretion.

Earnings that the account accrues also can be withdrawn tax-free—but with some conditions. Generally, they cannot be withdrawn until the account has been open for five years and you reach age 59½; otherwise, you could incur taxes and penalties. If the earnings do meet both of those conditions, they are called qualified withdrawals. And qualified withdrawals are exempt from income tax.

Many employees rely on the retirement savings accumulated through payroll deferrals made to an employer-sponsored savings plan such as a 401(k). However, IRAs allow anyone—even the self-employed—to contribute during their working years to ensure financial stability later in life.

How a Roth IRA Works

Whenever the investments in your account earn a dividend or interest, that amount is added to your account balance. How much the account earns depends on the investments that they contain. Remember, IRAs are accounts that hold the investments you choose. (They are not investments on their own.) Those investments put your money to work, allowing it to grow and compound.

Your account can grow even in years when you aren’t able to contribute. You earn interest, which gets added to your balance, and then you earn interest on the interest, and so on. The amount of growth that your account generates can increase each year because of the magic of compound interest.

Here’s an example: Assume that you contribute $3,000 to your Roth IRA each year for 20 years, for a total contribution of $60,000. Keep in mind that in 2023, you can contribute $6,500, or $7,500 if you're age 50 or older ($7,000, or $8,000 in 2024), provided that you meet the income limits.

In addition to your contributions, your account earns a very modest $5,000 in interest, giving you a total balance of $65,000. To ramp up your savings, you decide to invest in a mutual fund that yields 8% interest annually.

Even if you stop contributing to your account after 20 years, you earn 8% on the full $65,000 going forward. The next year, you earn $4,800 in simple interest ($60,000 in contributions multiplied by 8%) and $400 in compound interest ($5,000 of earnings multiplied by 8%). This increases your account balance to $70,200.

The following year, you continue to earn 8% on the sum of your contributions and previous earnings, yielding another $5,616 in total interest. Your balance is now $75,816. You gained nearly $11,000 in just two years without making any additional contributions. In the third year, you earn $6,065, increasing your balance to $81,881.

If you fast forward another five years, your account earns another $38,429 in interest, and your total balance is $120,310. Without making any contributions to it, your Roth IRA has nearly doubled in the past eight years through the power of compound interest.

No Required Minimum Distributions (RMDs) for Roth IRAs

With traditional IRAs, you have to start taking required minimum distributions (RMDs) when you reach age 73, even if you don’t need the money. That’s not the case with a Roth IRA. You can leave your savings in your account for as long as you live, and you can keep contributing to it indefinitely, as long as you have qualifying earned income and yourmodified adjusted gross income (MAGI) doesn’t exceed the annual limitfor making contributions.

These features make Roth IRAs excellent vehicles for transferring wealth. When yourbeneficiary inherits your Roth IRA, generally, they will have to take distributions that could be stretched out over 10 years. This can provide years of tax-free growth and income for your loved ones.

Max Out Your 401(k) Match First

Of course, a Roth IRA shouldn’t be the only way that you work on building a nest egg. If you have access to a 401(k) or similar plan at work, that’s another great place to save for retirement. Here’s why:

• If you get an employer match, you get an automatic 100% return on part of the money that you invest in your 401(k).
• 401(k)s are tax deferred, so your money grows faster.
• You get a tax deduction for the year when you contribute, which lowers your taxes (and gives you more to invest).
• There are high contribution limits: In 2023, you can contribute $22,500, or $30,000 for those over age 50 ($23,000 and ($30,500 for 2024).

A good strategy is to fund your 401(k) first to ensure that you get the full match, then work on maxing out your Roth. If you have any money left, you can focus on rounding out your 401(k).

The Bottom Line

Roth IRAs take advantage of the power of compounding. Even relatively small annual contributions can add up significantly over time. Of course, the sooner you get started, the more you can take advantage of compounding—and the better your chance of having a well-funded retirement.