If you want to retire a millionaire, your 401(k) can be an incredibly powerful tool to get you there. Indeed, if you use it well, you might even be able to reach millionaire status just from your 401(k) plan on its own.

Yet as powerful as a well-invested 401(k) plan can be, it's not a magic money making machine. You need to use it properly for it to give you your best shot of building that million-dollar nest egg. These three secrets of 401(k) millionaires can give you the foundation you need to make the most of your plan.

401k nest egg on a pile of cash.

Image source: Getty Images

No. 1: Start early

The following table shows how much you will need to sock away each month to wind up with $1 million in your 401(k), depending on the rate of return you earn and the number of years you'll be investing in it.

The longer your timeframe, the less you have to sock away each month to reach that target. Indeed, even if your returns end up being lower than the market's historical long-run rate near 10% annualized, you're still better off starting early than waiting until later in your career.

Years to Go

10% Annual Returns

8% Annual Returns

6% Annual Returns

4% Annual Returns

45

$95.40

$189.59

$362.85

$662.48

40

$158.13

$286.45

$502.14

$846.05

35

$263.39

$435.94

$701.90

$1,094.41

30

$442.38

$670.98

$995.51

$1,440.82

25

$753.67

$1,051.50

$1,443.01

$1,945.04

20

$1,316.88

$1,697.73

$2,164.31

$2,726.47

Data source: author.

No. 2: Maximize your match

If your employer offers you a 401(k) match, investing enough to maximize that match is hands down the first investment you should make. That match represents money available to you only if you make your own contribution to your 401(k).

It's also very likely the highest "guaranteed" rate of return you'll ever earn. While matches vary by company, a common one is 50% of your contribution amount, up to some percentage of your salary . If you get a match like that, then for every $1,000 you invest up to your match limit, your employer will add $500 to your account.

That acts like an immediate 50% return on your investment. On top of that, once it's in your account, that money can then continue to grow on your behalf alongside the rest of your investments.

Put it all together, and it can quickly become obvious why this secret is such a powerful tool for those looking to reach millionaire status from their 401(k)s.

No. 3: Invest based on a percentage of your salary

People under age 50 can generally contribute up to $23,000 per year to their 401(k) plans, while those age 50 and up see their limits as high as $30,500. While those are the upper limits, you don't have to max out your plan to make great progress toward your goal.

With that in mind, many plans will allow you to choose your contribution amount based on a percentage of your salary, rather than based on a specific dollar amount. If you have the ability to do so and aren't maxing out your plan, then it typically is a great idea to set your contribution based on a percentage of your salary.

This is because doing so will automatically increase your contribution amount every time you get a raise. If you earn $50,000 and contribute 10% of your salary, that's $5,000 you're socking away. If your salary increases to $52,000, that same 10% contribution will automatically grow to $5,200.

Using that approach makes it easier for you to continue boosting your savings over time, since your contribution will increase as your salary does. If you can't save enough today to get you on track to that millionaire status, making a commitment to increase your contribution amount as you're able to can help you get closer over time.

Get started now

These three not-so-secret secrets of 401(k) millionaires all work together to help those folks build their wealth. The sooner you get started putting the secrets to use for yourself, the better your chances are of joining those who've amassed that $1 million nest egg. So get started now, and give yourself the longest runway possible to get yourself to that spot.