What could $500 a month in ASX 200 shares become in 20 years?

Building wealth doesn't require a lump sum. Here's what regular investing in ASX shares could achieve over time.

Investing doesn't have to start with a large lump sum.

Putting $500 a month into ASX 200 shares might not feel like much at first, but over time, it can build into something meaningful.

I'm going to show you how.

Young businesswoman sitting in kitchen and working on laptop.

Image source: Getty Images

The power of compounding

The real driver here is compounding. That's where your returns start generating their own returns, and the effect builds over time.

If we assume a long-term return of 9% per annum, which is not guaranteed but has been achievable historically over long periods, the numbers start to add up.

After 10 years, a $500 monthly investment could grow to around $95,000.

By 20 years, that same approach could see your portfolio reach approximately $320,000.

What stands out to me is how much the growth accelerates in the second decade. That's compounding doing the heavy lifting.

Why consistency matters

One of the biggest advantages of investing regularly is that it removes the pressure to time the market.

When you invest every month, you naturally buy more ASX 200 shares when prices are lower and fewer when prices are higher.

This is known as dollar-cost averaging.

It's a simple approach, but I think it's incredibly effective.

Instead of trying to predict short-term movements, you're steadily building your position over time.

Not every year will look the same

A 9% average return doesn't mean you'll get 9% every year.

Some years will be strong, with double-digit gains. Other years may be flat or even negative. That's part of investing in ASX 200 shares.

Volatility is normal, especially over shorter periods.

What matters is staying focused on the long term and not getting distracted by short-term fluctuations.

The role of quality

If I were following this approach, I'd want to focus on quality ASX 200 shares or broad market exposure.

This might include ResMed Inc. (ASX: RMD), Macquarie Group Ltd (ASX: MQG), Hub24 Ltd (ASX: HUB), and Wesfarmers Ltd (ASX: WES).

These are businesses that have proven their ability to grow over time, generate profits, and adapt to changing conditions.

Over long periods, quality tends to win out. And when combined with regular investing, it can create a powerful foundation for wealth building.

Why starting matters

The earlier you begin, the more time compounding has to work.

But I think even starting later can still make a big difference.

What matters most is getting into the habit of investing consistently and sticking with it.

Because over time, those monthly contributions can turn into something far larger than they first appear.

Foolish takeaway

Investing $500 a month into ASX 200 shares may seem simple, but over 20 years, it could grow into around $320,000 based on a 9% annual return.

For me, this highlights what really drives long-term results. Consistency, patience, and letting compounding do its work.

Motley Fool contributor Grace Alvino has positions in Hub24 and Wesfarmers. The Motley Fool Australia's parent company Motley Fool Holdings Inc. has positions in and has recommended Hub24, Macquarie Group, ResMed, and Wesfarmers. The Motley Fool Australia has positions in and has recommended Macquarie Group and ResMed. The Motley Fool Australia has recommended Hub24 and Wesfarmers. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Scott Phillips.

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