Many of us dream of retiring as millionaires. But life's little surprises often get in the way of our best-laid plans. Whether from raising kids, caring for aging parents, or facing unanticipated health- or home-related expenses, a lot can get in the way of investing for our futures.

If you started and then stopped investing for your retirement, you probably still have some money socked away for your future. Perhaps it's hiding out in an IRA or former employer's 401(k) plan. Whatever the amount, your existing nest egg is valuable seed money to help you restart the quest to retire a millionaire.

What does it matter?
Ultimately, how much you wind up with depends largely on three key factors:

  • How much you invest.
  • How long you invest for.
  • What rate of return you earn on your investments.

Money that you've already got working for you can compound on your behalf, even if you don't invest another dime. The table below shows the number of years it'll take you to amass that $1 million, depending on how much you start with, how much you save each month, and what rate of return you earn. As you can tell, even restarting from a relatively small $10,000 base can take years off the time it'll take to get there:

Starting Amount

Monthly Contribution

10% Annual Returns

8% Annual Returns

6% Annual Returns

4% Annual Returns

$0 $100 44.5 52.9 65.7 88.6
$0 $500 28.8 33.4 40.1 51.0
$0 $1,000 22.4 25.5 29.9 36.7
$10,000 $100 38.4 46.5 58.9 81.3
$10,000 $500 27.3 31.8 38.5 49.4
$10,000 $1,000 21.6 24.7 29.1 35.9
$50,000 $100 28.0 34.5 44.8 64.0
$50,000 $500 22.7 27.0 33.3 43.8
$50,000 $1,000 18.9 21.9 26.2 32.9
$100,000 $100 22.1 27.3 35.8 51.8
$100,000 $500 19.0 22.8 28.5 38.2
$100,000 $1,000 16.3 19.1 23.2 29.5

How to restart
If life got in the way of your initial investing plans, it's perfectly fine to restart investing now by putting aside what you can, when you can. In addition to the benefits you get from the money you've already invested, what's also clear from that chart is that the more you put away, the quicker you'll hit that $1 million target. So even if you restart slowly, your future self will thank you tremendously if you ramp up your investing as your financial situation allows.

In most situations, investing a small amount of cash at a time is a sure way to get your wealth confiscated by commissions paid to your broker. There is one class of investment, however, that often welcomes small contributions and does so with little or no fees attached. They're called dividend reinvestment plans (aka DRIPS), and there are several that will let you efficiently invest $100 or less at a time.

The table below shows a few small-investor friendly DRIPs that offer the ability to contribute and reinvest dividends with no fees:

Company

Initial Enrollment

Minimum Optional Contribution

More Information

Abbott Laboratories (NYSE: ABT) 1 share of stock $10 Click Here
El Paso Corp. (NYSE: EP) 1 share of stock $50 Click Here
Hasbro (NYSE: HAS) 1 share of stock $25 Click Here

Of course, investing in individual stocks instead of exchange-traded or mutual funds does expose you to company-specific risks of loss in addition to overall economic risks. While I'm not predicting Abbott Labs to go out of business anytime soon, there's always a chance of it happening. So if you're concerned about those risks, you can also invest in broader funds.

While broader funds give you the benefits of instant diversification, there's a trade-off. You have to pay for the funds' management above and beyond the company management, and may also owe commissions. Additionally, the higher a fund's turnover rate, the more hidden costs you're exposed to due to that churn. Those costs and risks need to be balanced with the broader diversification benefit of fund-focused investing.

The table below shows a handful of pretty well-diversified ETFs with low expenses and turnover rates:

Fund

What it Tracks

Expense Ratio

Turnover

SPDR S&P 500 (NYSE: SPY)

The US S&P 500:

large-cap U.S. stocks

0.09% 5%
Vanguard Total World Stock (NYSE: VT) The FTSE All World Index: large-cap worldwide stocks 0.25% 7%
Vanguard All World ex US Stock (NYSE: VEU) The FTSE All World Index excluding U.S. stocks 0.22% 6%

Whether you're looking to buy American, own the world, or hedge the risk of an American economic collapse, there are low-cost, low-churn ETFs that can let you invest inexpensively.

Plant new seeds and water well
Regardless of how long it has been since you've actively invested for your future, you can get restarted now. Just remember that your ultimate net worth depends on how much you can sock away, the length of time you invest, and your overall rate of return. The more cost-efficiently you invest, the better your chances of success.

At the time of publication, Fool contributor Chuck Saletta did not own shares of any company or fund mentioned in this article. Coca-Cola is a Motley Fool Inside Value selection. Hasbro is a Motley Fool Stock Advisor recommendation. Hasbro and Coca-Cola are Motley Fool Income Investor recommendations. The Fool owns shares of Abbott Laboratories, Coca-Cola, and El Paso. Alpha Newsletter Account, LLC owns shares of Abbott Laboratories. Try any of our Foolish newsletter services free for 30 days.

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