I'd been meaning to open a Roth IRA since freshman year. Every time it came up in an econ lecture I'd nod along, add it to a mental list, and then go back to worrying about a problem set due at midnight. This week I finally opened one, not because I suddenly had more money, but because I ran a number that made "later" feel expensive.
Here's the setup. Same person, same $200 a month, same 8% average annual return. The only thing that changes is when they start.
Investor B puts the exact same $200/month, starting at 30 instead, and also stops at 60.
Investor A contributes for 40 years. Investor B contributes for 30 years, ten fewer years, same monthly amount. At 8% average annual return, compounded monthly:
Investor A: roughly $698,000 by 60.
Investor B: roughly $298,000 by 60.
Same $200. Same discipline. The only difference is a ten-year head start, and it's worth roughly $400,000.
That's not a rounding error. That's the entire cost of waiting, priced in dollars instead of vague guilt about "should probably start investing soon."
Why the gap is so much bigger than ten years' worth of contributions
Ten years of $200/month is $24,000 in contributions. The actual gap between the two outcomes is roughly $400,000. The difference isn't the money you put in during those first ten years. It's the decades that money then had to compound on top of itself before you ever touched it. Money invested at 20 gets to compound through your entire 20s, 30s, 40s, and 50s. Money invested at 30 only gets three of those decades.
This is the part that doesn't show up in a checking account balance and doesn't feel urgent when you're deciding between a Roth IRA contribution and literally anything else happening in your actual life right now. The opportunity cost of waiting isn't visible today. It's only visible thirty years from today, which is exactly why it's so easy to defer.
What I actually did
I opened the account with an amount that didn't require me to change anything else about how I live right now: small enough that I won't quietly stop contributing in October, automated so I don't have to remember to do it. The number matters less than the habit starting today instead of "once I have more money," because there is always a version of the future where you have more money and a shorter runway for it to compound.
Check irs.gov for the current annual contribution limit before you open an account. It's adjusted periodically and I'm not going to print a number here that might be stale by the time you read this.
This is a hypothetical example for illustration only, assuming a fixed 8% average annual return compounded monthly. Real markets don't move in a straight line, and past performance doesn't guarantee future returns. This isn't personalized financial advice. Talk to a licensed advisor about your own situation.
