Adults have been saying "start saving young" to teenagers for as long as teenagers have existed. It is one of those pieces of advice that sounds right but never comes with enough explanation to actually motivate anyone to act on it. Nobody tells you the specific numbers. Nobody shows you what the math looks like over 49 years. I got curious and ran it myself, and the outcome was genuinely surprising enough that I wanted to write it down.
The short version: a dollar invested at 16 is worth almost three times as much at retirement as the same dollar invested at 30. Not because of anything you do differently. Not because you pick better stocks or take more risk. Just because it has more time to compound. Once you see that number clearly, the question stops being "should I open a retirement account?" and becomes "why would I wait even one more year?"
A Roth IRA is a retirement savings account where you invest money you have already paid income tax on. The core deal: pay taxes now, and everything that money grows into over the next several decades comes out tax-free at retirement. No capital gains tax on 49 years of appreciation. No income tax on withdrawals. The government gets its cut once, upfront, and after that every dollar of growth belongs entirely to you.
That structure is most valuable to someone who is young and earns relatively little, which describes most 16-year-olds almost perfectly. Your effective income tax rate right now is probably the lowest it will ever be in your adult life. Paying taxes on $3,000 of summer job income costs you very little. Paying taxes on $3,000 of retirement withdrawals decades from now, when you presumably earn more, would cost you significantly more. The Roth front-loads the tax burden at the cheapest possible moment.
The contribution limit in 2026 is $7,000 per year. The catch is that you need earned income to contribute: wages from a job, self-employment income, documented freelance work. Gifts, allowances, and investment income do not count. Your contribution is capped at the lesser of $7,000 or your actual earned income for the year. You can open a custodial Roth IRA at Fidelity, Vanguard, or Charles Schwab with a parent listed as custodian until you turn 18. Most of them have no minimum balance and the account takes about 30 minutes to open online.
The S&P 500 has returned approximately 10% annually on average since its inception, or about 7% after adjusting for inflation. That 7% real return is what I'll use because it accounts for the fact that a dollar in 49 years is worth less than a dollar today.
$1,000 invested at 16 at 7% real annual return reaches approximately $15,000 by age 65. That same $1,000 invested at 30 reaches about $5,400. The math is just the compound interest formula: A = P x (1 + r)^n. At 16 you have n = 49 years. At 30 you have n = 35 years. Fourteen fewer years of compounding reduces the outcome by roughly 64%. You are not taking more risk at 30. You are just losing time, and time is what does most of the work.
The single investment illustration is useful for understanding the mechanism but it is not how most people use these accounts. The realistic scenario is putting in a few hundred to a couple thousand dollars each year from a job. Even modest contributions become significant money over long enough time horizons.
$1,000 a year invested from age 16, in a basic S&P 500 index fund, grows to about $390,000 by age 65. $2,000 a year gets you to roughly $780,000. $5,000 a year, which approaches the contribution limit, gets you close to $1.95 million. None of that requires stock picking, market timing, or any particular financial sophistication beyond the discipline of contributing consistently. The index fund does the work. The account structure does the tax protection. Time does most of the heavy lifting.
Consider what the Roth structure saves you on the back end. If you had that $780,000 in a regular taxable brokerage account instead, withdrawing it in retirement would trigger capital gains tax on every dollar of appreciation above your original contributions. Depending on your income level and the composition of the gains, you might owe 15% to 20% on the bulk of it. On $780,000 that could easily be $100,000 to $150,000 in taxes. In a Roth, that is $0. The tax wrapper is not a minor administrative detail. It represents a meaningful fraction of the account's eventual value.
You cannot touch the earnings before age 59 and a half without paying a 10% penalty plus income tax on the amount withdrawn. This sounds like a downside and technically is one. But practically, it is what makes the account work as a retirement vehicle rather than just a savings account you eventually spend. It makes it inconvenient to raid decades of compounding for near-term expenses. One important nuance: you can withdraw your actual contributions at any time without penalty. The restriction applies to the earnings only. So this is not money trapped beyond all reach in a real emergency. It is money that is structurally discouraged from being spent casually, which is exactly the point.
If you have any earned income at all, the answer is yes. Get a job, even part-time, even seasonal. Contribute whatever you earned up to the $7,000 limit. Put it in a total market index fund or an S&P 500 fund and let it sit. Do not check it constantly. Do not try to time the market. The account will have bad years. The S&P 500 dropped 19% in 2022. It recovered all of that and more within 18 months. The strategy is not to avoid those drops. It is to stay invested through them and collect the long-run average.
The adults who tell you they wish they had started earlier are telling you something true and specific. The dollars you invest at 16 are the most powerful financial asset you will ever have access to in terms of time value. They get 49 years of compounding. The dollars you invest at 30 get 35. That difference is not small, and it does not close. The window to capture it is exactly right now.