Building a portfolio worth $1 million or more isn't easy, but the right investments can get you there with enough time and consistency.

Investing in exchange-traded funds (ETFs) can help you make a lot of money with minimal effort. Each ETF contains dozens of stocks bundled together into a single fund, making it one of the simplest ways to build a diversified portfolio.

Not all ETFs are created equal, but if you're looking to build long-term wealth, these three Vanguard funds could be a fantastic place to start.

Stack of hundred dollar bills against a yellow backdrop.

Image source: Getty Images.

1. Vanguard S&P 500 ETF

The Vanguard S&P 500 ETF (VOO 0.02%) tracks the S&P 500 index (^GSPC 0.05%), containing stocks from 500 of the largest companies in the U.S. The S&P 500 is often considered to represent the stock market as a whole, as it covers around 80% of total market capitalization.

When you invest in an S&P 500 ETF, then, you're essentially buying a small slice of the stock market. This can provide immediate diversification, as you'll own a stake in all 500 companies within the index.

This ETF can be a smart option for those looking to limit risk, because the companies within the S&P 500 are among the strongest in the world. They can still take a turn for the worse during a market downturn, but many of them have decades of experience surviving periods of volatility -- and they're very likely to bounce back after future slumps, too.

At the same time, though, this ETF can help you build life-changing wealth over time. The market itself has historically earned an average rate of return of around 10% per year, which could turn $200 per month into just over $1 million after 40 years.

2. Vanguard S&P 500 Growth ETF

If you're looking for the relative safety of an S&P 500 ETF with a bit more punch, the Vanguard S&P 500 Growth ETF (VOOG 0.16%) could be a fantastic choice. This ETF also follows the S&P 500, but it only includes 209 stocks from the index that have the most potential for growth.

Investing in this ETF can help balance risk and reward. While you won't have as much variety and diversification as you would with an S&P 500 ETF, an S&P 500 Growth ETF can often earn higher returns over time.

In fact, over the last 10 years, the Vanguard S&P 500 Growth ETF has earned an average rate of return of around 15% per year. At that rate, if you were investing $200 per month, you could reach $1 million in around 30 years.

3. Vanguard Information Technology ETF

The Vanguard Information Technology ETF (VGT 0.03%) is riskier than the other two funds on this list, but it's also a powerhouse of an investment that could supercharge your savings.

This ETF contains 316 stocks, all of which are from various corners of the technology industry. Tech stocks can carry more risk than companies from other sectors, as they're often more volatile -- especially in the short term. But they are also known for their explosive growth.

Over the last 10 years, this ETF has earned an average rate of return of close to 21% per year. If you were investing $200 per month at that rate, it would take around 24 years to accumulate $1 million.

Keep in mind, though, that there are no guarantees this ETF will continue earning these types of returns. Even if it does, the short term can still be incredibly volatile -- so be prepared for potentially severe ups and downs if you choose to invest.

VOO Chart

VOO data by YCharts

Reaching $1 million often takes decades of consistent investing, and it's important to look at factors beyond an ETF's annual returns. For example, while the Vanguard Information Technology ETF's earnings history is compelling, it can be incredibly risky to invest solely in tech stocks.

For a more balanced approach, you may decide to invest in multiple ETFs or simply add an ETF to your existing portfolio. By ensuring you're diversifying properly and keeping a long-term outlook, you're far more likely to see positive returns over time while still protecting your portfolio as much as possible.