I’m 29 with $45k in my 401k and the calculators are telling me I’ll have $4 million by the time I’m 65 – is that really accurate?

Key Points from 24/7 Wall St.

• Funding a 401(k) over a long period of time could make you a millionaire several times over.
• Keep in mind that your buying power will erode over time due to inflation.
• Aiming to save and invest as much as you can is your best bet.
• Retiring early is possible and may be easier than you think. Click here now to see if you’re ahead, or behind. ^(Sponsor)

At age 29, your 401(k) balance may not be all that impressive. That’s because most people have only been working for a short amount of time by that point. And also, a lot of people in their 20s can’t max out a 401(k) because they’re not earning all that much and have student debt and other bills to pay.

But if you keep funding your 401(k) over time and invest your money wisely, you might wind up with millions of dollars by the time you’re ready to retire thanks to the power of compounded returns. And that ties into this Reddit post: a 29-year-old with $45,000 in their 401(k) is asking if it’s really possible to retire with $4 million.

The poster used an online retirement calculator, which told them they’d be looking at a balance that large if they keep up their current 10% to 12% savings rate and continue to generate strong returns. They’re happy with the numbers they’re seeing on screen, but they want to know how accurate they are. (Generic calculators often assume constant returns and contributions, which rarely happen exactly that way.)

The reality is that it’s possible to retire with $4 million in this scenario. But there’s a bit more to the story than that.

This post was updated on October 31, 2025 to include a note on generic investment calculators, a more conservative estimation on 401(k) value over time, and a look at what inflation would do to $4 million in 36 years.

What does a $4 million retirement actually look like down the line?

For someone retiring today at a traditional retirement age, $4 million is a lot of money. It may not hold up as well 36 years from now, though, which is when the poster above may be getting set to start their retirement.

Inflation erodes the power of money over time. So, while retiring with $4 million could make for a very comfortable lifestyle today, it might take more like $8 million to allow for a comfortable retirement three and a half decades down the line. (At 3% annual inflation, prices roughly double every 24 years, meaning $4 million today would equal roughly $8 million in 36 years to maintain equal buying power.)

So the quick answer to the poster’s question is that yes, it’s possible for a nest egg that’s only worth $45,000 at age 29 to be worth $4 million at 65 if they save at a high rate and generate strong returns in their portfolio. But it’s not guaranteed, either. And even if they end up retiring with $4 million, whether it will be enough depends on what they want their retirement to look like.

When we factor inflation into the mix, a $4 million nest egg, even 35 years from now, won’t be anything to scoff at. However, it likely won’t make for the luxury retirement that sum could produce today; it’s important to be aware of that.

Additionally, readers should note that 10% annualized return is aggressive by historical standards. Long-run stock-market real returns average about 7% nominal, 4 %–5 % real. Using more conservative assumptions (7% nominal, 3% inflation) would yield a future balance closer to $2–2.5 million, not $4 million, if contributions stay constant.

Keep saving and investing

I have two pieces of advice to the poster above, and anyone else in their 20s who’s wondering what to expect out of their retirement savings. First, keep funding your 401(k) or IRA or whatever account you’re using as best as you can. Secondly, make sure you’re taking advantage of investments that have the power to well outpace inflation.

For the latter part, I’d suggest sitting down with a financial advisor and having them recommend a mix of assets based on your age and investment horizon. An advisor can also use the tools they have to run the numbers and help you get a sense of what your spending power in retirement might be based on your savings plans.