These 2 simple ASX index funds could turn $100 a month into $1 million

Index funds can help anyone build wealth on the stock market…

A young couple hug each other and smile at the camera standing in front of their brand new luxury car

Image source: Getty Images

You’re reading a free article with opinions that may differ from The Motley Fool’s Premium Investing Services. Become a Motley Fool member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn More

ASX index funds are a great way of investing in the share market without the onerous requirements of researching and picking individual shares.

Many investors love the thrill of finding the next big stocks or building their own stock portfolios from scratch. But for others, a hands-off, passive approach is preferable.

For the latter, index funds are arguably a great choice. An index fund allows investors to invest in hundreds of individual shares, all in one easy ticker code. This provides instant diversification, as well as delivering what could be considered the 'average' return of a market over a long period of time.

If you are disciplined enough, and have enough cash to invest, you can even turn a $100 per week investment into a nest egg worth up to $1 million using these index funds.

Let's discuss how, using two examples.

Building wealth with ASX index funds

The first is the most popular index fund on the ASX – the Vanguard Australian Shares Index ETF (ASX: VAS).

This ASX index fund represents an investment in the largest 300 stocks on the Australian share market. That includes everything from Commonwealth Bank of Australia (ASX: CBA), Telstra Group Ltd (ASX: TLS) and Woolworths Group Ltd (ASX: WOW) to JB Hi-Fi Ltd (ASX: JBH), Harvey Norman Holdings Ltd (ASX: HVN) and Ampol Ltd (ASX: ALD).

The second is the iShares S&P 500 ETF (ASX: IVV). This index fund doesn't track ASX shares but instead allows ASX investors to hold the largest 500 companies listed on the American stock markets. In this fund, you'll find names like Apple, Coca-Cola, Microsoft and Colgate-Palmolive.

As of 30 September, the Vanguard Australian Shares ETF has returned an average of 8.89% per annum over the past ten years. That includes returns from both price growth and dividends.

Over the same period, the iShares S&P 500 ETF has returned an average of 15.8% per annum.

Now, let's assume these rates of return will hold going forward (which is by no means guaranteed, of course). For someone who begins investing $100 a week at age 20, reinvests all dividends like clockwork, and continues to invest every single week, rain, hail or shine, it would get them to a portfolio value of $1 million by the time they are 53 (or after 33 years).

For our 20-year-old investor, that should set them up for a rather comfortable retirement.

However, if that same investor uses the iShares S&P 500 index fund and invests that same $100 a week, it would take just 22 years to get to seven figures. An early retirement might be on the cards there.

Foolish takeaway

Of course, these numbers are completely hypothetical. There's every possibility that either of these index funds doesn't deliver the same returns they have over the past decade going forward.

But what we can count on is the power of compounding, and the effectiveness of consistently investing to build wealth. Those are the powers that we must harness if we wish to succeed in passive investing.

Should you invest $1,000 in Ampol Limited right now?

Before you buy Ampol Limited shares, consider this:

Motley Fool investing expert Scott Phillips just revealed what he believes are the 5 best stocks for investors to buy right now... and Ampol Limited wasn't one of them.

The online investing service he’s run for over a decade, Motley Fool Share Advisor, has provided thousands of paying members with stock picks that have doubled, tripled or even more.*

And right now, Scott thinks there are 5 stocks that may be better buys...

See The 5 Stocks *Returns as of 6 March 2025

Motley Fool contributor Sebastian Bowen has positions in Apple, Coca-Cola, Microsoft, Telstra Group, and Vanguard Australian Shares Index ETF. The Motley Fool Australia's parent company Motley Fool Holdings Inc. has positions in and has recommended Apple, Microsoft, and iShares S&P 500 ETF. The Motley Fool Australia's parent company Motley Fool Holdings Inc. has recommended the following options: long January 2026 $395 calls on Microsoft and short January 2026 $405 calls on Microsoft. The Motley Fool Australia has positions in and has recommended Harvey Norman and Telstra Group. The Motley Fool Australia has recommended Apple, Jb Hi-Fi, Microsoft, and iShares S&P 500 ETF. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Scott Phillips.

More on Index investing

Cubes placed on a Notebook with the letters "ETF" which stands for "Exchange traded funds".
ETFs

If I could only buy 1 ASX ETF, it would be this one

This ETF simply covers all bases...

Read more »

ETF written on wooden blocks with a magnifying glass.
ETFs

VAS vs VHY: Which is the better Vanguard ETF?

A higher yield isn't always the best choice.

Read more »

A woman looks questioning as she puts a coin into a piggy bank.
Index investing

The Vanguard US Total Market ETF (VTS) is down 8% from its peak. Is it time to buy?

Like many index funds, VTS is looking cheap right now.

Read more »

ETF written on wooden blocks with a magnifying glass.
ETFs

Meet the 2 new Vanguard ETFs that just hit the ASX

Vanguard has something for everyone with these new funds...

Read more »

A man casually dressed looks to the side in a pensive, thoughtful manner with one hand under his chin, holding a mobile phone in his hand while thinking about something.
Index investing

Vanguard Australian Shares ETF (VAS): Should we be worried about CBA?

Has CBA grown too big for VAS' boots?

Read more »

A businessman looking at his digital tablet or strategy planning in hotel conference lobby. He is happy at achieving financial goals.
Index investing

Is the Vanguard Australian Shares Index ETF (VAS) a buy at $105?

It can still be a good idea to buy index funds when they look expensive...

Read more »

ETF spelt out with a piggybank.
Index investing

2 reasons to buy the Vanguard MSCI Index International Shares ETF (VGS) today (and 1 not to)

This index fund is popular, but there's a big catch.

Read more »

A person sitting at a desk smiling and looking at a computer.
Index investing

ASX index funds: Which is the best buy today?

When it comes to index funds, I think it's best to keep things simple.

Read more »