Building a $1 million portfolio with ASX shares and the magic of compound interest

Investors can supercharge their long-term gains by tapping into the magic of compound interest.

Building a $1 million portfolio from ASX shares may sound out of reach for many investors.

They may think it would take a lifetime. Or that you'd need a sizeable cash pile to even get started.

But by tapping into the power of compound interest and keeping a long-term investing mindset, these investors might be surprised at the time and size of the initial investments it could take to achieve that $1 million from ASX shares.

Let's have a closer look.

A businesswoman in a suit and holding a briefcase marches higher as she steps from one stack of coins to the next.

Image source: Getty Images

Two ways to go

Newer investors, or those short on research time, might want to stick to a more passive approach to investing in ASX shares.

You can do this by investing in a wide range of ASX exchange-traded funds (ETFs), which offer diversification with a single stock.

Some ETFs track particular market sectors, from gold miners to financial stocks. Others are intended to mimic the performance of an entire index, like the S&P/ASX 200 Index (ASX: XJO).

Look for ETFs with low management fees, so as not to eat into your long-term, compound interest boosted returns.

If you're comfortable picking your own ASX shares, or have access to some trusted advice, this opens the door to potentially higher returns, though with some added risk.

Here's what I mean.

On the higher return end, shares in Nuix Ltd (ASX: NXL), which develops and distributes software, are up a whopping 108% in 2023.

And shares in Codan Ltd (ASX: CDA), which provides products and services in communications, metal detection and mining technology, have soared 92% this calendar year.

You're really unlikely to find those kinds of returns with ETFs.

So, what about those risks?

Well, if you'd invested in gold miner St Barbara Ltd (ASX: SBM) on 3 January this year, you'd be nursing a loss of 36% today.

And investors who bought into biotech company Mesoblast Ltd (ASX: MSB) on 3 January will be down 53%.

So, if you're going to be picking individual ASX shares to build your wealth, choose wisely.

How long will it take to reach $1 million with ASX shares?

The amount of time it will take to reach my $1 million goal will depend on two factors.

How much I invest each month, and what types of returns I manage.

Now, there are no guarantees as to future returns.

But in building my ASX share portfolio, I'll aim for an average annual return of 10% to 11%. And I'll plan to reinvest any dividends I get to help boost those returns.

Splitting the difference here, I'll be happy to achieve 10.5% returns over the long term.

And I'll diligently put aside $200 each week, or $10,400 a year, to invest.

Now let's plug those figures into the old compound interest calculator.

Here's what it tells me:

After five years the total value of my ASX share portfolio will be $64,128. That rises to $169,775 after 10 years and $630,560 after 20 years.

Just five years later, after 25 years, the total value of my investments will be $1,102,942.

That's a tidy sum.

And, thanks to the magic of compound interest, I'll have only invested $260,000 of my hard-earned money to get there.

Motley Fool contributor Bernd Struben has no position in any of the stocks mentioned. The Motley Fool Australia's parent company Motley Fool Holdings Inc. has no position in any of the stocks mentioned. The Motley Fool Australia has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Scott Phillips.

More on How to invest

Businesswoman working from home with stock market chart showing percent change on her laptop screen.
How to invest

Could just 2 ASX ETFs be enough to build serious wealth?

Investing does not need to be complicated. These two funds could cover a lot of ground

Read more »

Happy investor on tablet with finance graphs rising in overlay.
How to invest

I've given myself 25 years to turn $10,000 a year into $1 million on the ASX. Here's how I plan to do it

I crunch the numbers to see what it would take to turn these annual investments into $1 million.

Read more »

Inflation ahead written in black on a yellow sign.
How to invest

Higher for longer: How to invest in a high-inflation Australia

If inflation is here to stay, we have to invest accordingly.

Read more »

woman using affirm to pay
BNPL shares

Zip shares are doing a 5-for-1 consolidation. Does this make Zip shares worth more or less?

After a rough week for Zip shareholders, I discuss some common investing myths through the lens of the upcoming Zip…

Read more »

Man reading his emails on a laptop while relaxing on a beach.
How to invest

If I could only check my ASX portfolio once a year, these are the 10 shares I'd own

I look at the shares I'd feel comfortable leaving alone for 12 months at a time.

Read more »

A group of seven young people of different genders and cultural backgrounds stand in a group with serious expressions wearing casual young persons' attire.
How to invest

What does the average Australian investor in 2026 look like?

Their age, income, portfolio size, and investing habits revealed.

Read more »

Watering can pouring water on increasing piles of coins with green plants on them and a piggy bank and coins on the table.
How to invest

The 3 factors that have helped me build a six-figure ASX share portfolio at 35

This financial plan is helping me build towards significant wealth.

Read more »

Five friends enjoying acai bowls at a cafe.
How to invest

How to build a $52,000 passive income with ASX shares

Want your money to work for you? Here's how you could do it.

Read more »