Only 15% of Americans consider themselves wealthy, a survey from MagnifyMoney found, but more than half believe they'll be wealthy someday. And if you're aiming to retire a millionaire, that goal may be easier to achieve than you may think.

Reaching retirement age with $1 million or more in savings requires a strategic investing approach, and not everyone will be able to reach this goal. However, by taking these three steps, you can transform $100,000 into $1 million by the time you retire.

Young man holding hundred dollar bills

Image source: Getty Images.

1. Start saving early

When you're saving for retirement, your money relies heavily on compound interest to grow. The more time your savings have to compound, the faster they're able to snowball.

Ideally, you'll have started saving in your 20s and will continue to save consistently until you retire. But if you got off to a late start, you can still achieve your goal -- you'll just need to work a little harder.

No matter your age, it's best to start saving right now. Every year counts, and putting off saving will only make it more difficult to catch up later. If you're starting with $100,000 in savings, here's how much you'd need to save each month to reach $1 million by age 65, depending on the age you started investing.

Age You Began Saving Amount Saved Per Month Total Savings at Age 65
40 $375 $1.014 million
45 $1,000 $1.015 million
50 $2,100 $1.001 million
55 $4,550 $1.007 million
60 $12,500 $1.027 million

Source: Author's calculations, assuming an 8% annual return on investment

The earlier you get started saving, the better. Remember that saving even a little is better than doing nothing. So even if you can't afford to save much, starting now is better than waiting.

2. Invest aggressively (but not too aggressively)

Investing for retirement isn't a get-rich-quick scheme, and investing in risky stocks that you hope will pay off someday could be a recipe for disaster. That said, you'll also need to invest aggressively enough that you earn a relatively high rate of return.

It can be tempting to invest conservatively to protect your savings. However, being too safe can also have serious consequences.

When you invest in bonds and other conservative investments, your savings won't experience as many wild ups and downs during periods of volatility. However, they also won't grow nearly as much as if you'd invested in stocks. Saving $1 million is challenging even if you're earning an 8% or 9% annual return on your investments. If you're only earning a 4% or 5% annual return, you'll need to save significantly more each month to make up the difference.

That said, as you get older, you should start to invest more conservatively. This strategy can help protect your savings from market downturns when you're quickly approaching retirement age. When you still have decades left before you retire, though, it's wise to take a more aggressive approach.

3. Be willing to make financial sacrifices

Retiring a millionaire is possible, but it's not always easy. If you're behind on your savings or don't have much cash to spare each month, you may need to make budget cuts to save more.

Depending on how much you need to save each month, you might need to make some serious sacrifices. Consider whether you're willing to slash your budget down to the essentials to increase your savings rate. If your top priority is building a robust retirement fund, these budget cuts may be worth it. But if you're not able to make these sacrifices now, you may need to reassess your retirement goals.

Saving $1 million by retirement age is challenging, and it won't be the right goal for everyone. But if you're willing to work hard and supercharge your savings, retiring a millionaire may be within reach.