I'd imagine most Aussies would love to have a $1 million ASX share portfolio.

However, $1 million doesn't just appear out of nowhere unless someone inherits it or wins the lottery.

To reach a $1 million ASX share portfolio, we'd need to regularly save and invest to hit that target.

The question is – how long would it take to become a millionaire if someone were able to save $500 per month? In the current economic environment, for some households, attaining $500 per month of savings may be as far as their money can stretch. For other households, reaching $500 per month may be a comfortable target.

Whatever your financial position, let's assume that saver is able to put aside $500 every month.

Reaching $1 million with ASX shares

There are a wide variety of investments that Aussies can choose from to invest in.

To figure out how long it would take to become a millionaire, we need to assume what level of return the portfolio will achieve.

To start with, I'm going to use the historical return of the Vanguard Australian Shares Index ETF (ASX: VAS), an exchange-traded fund (ETF) that tracks the S&P/ASX 300 Index (ASX: XKO), which is 300 of the largest businesses on the ASX.

According to Vanguard, the VAS ETF has returned an average of 9.3% since May 2009.

If someone invested $500 per month and it grew by an average of 9.3% per year, it'd take less than 32 years to reach $1 million.

Can it be done quicker?

There are two main ways that an investor could reach $1 million faster. Obviously, the first one is simply to save more money each month.

The second way is to choose investments that could deliver stronger returns than 9.3% per year.

The global share market could be a very useful place to get exposure to because of the bigger businesses and the larger addressable market for the stocks involved compared to the ASX share market.

The Vanguard MSCI International Shares Index ETF (ASX: VGS) is an effective way to invest in the global share market. It has returned an average of 13.4% since its inception in November 2014.

If someone invested $500 per month and it grew by an average of 13.4%, it'd take less than 26 years to reach $1 million

Only investing in quality global shares could be an even better strategy for investors because it just focuses on the best of the best. For example, the VanEck MSCI International Quality ETF (ASX: QUAL) invests in 300 of the highest-quality businesses across the world. Since inception in October 2024, the QUAL ETF has returned an average of 15.8% per year.

If someone invested $500 per month and it grew by an average of 15.8% per year, it'd take less than 23 years to get to $1 million.

Of course, past performance is not a guarantee of future performance, but the above numbers show how stronger-performing investments can shave off years of an intended investment target. That's what Motley Fool is all about – finding (ASX share) investments that can produce good returns.