How to invest $300 a month in Australian shares to target a $50,000 annual second income

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There’s a big difference between investing and building an income machine.

Anyone can put money into Australian shares. But turning small, regular contributions into a portfolio that pays you $50,000 a year is about designing something with a clear end goal.

If you are investing $300 a month, here is how that journey could realistically unfold.

Think in terms of income

A $50,000 annual second income, based on a 5% dividend yield, requires a portfolio of around $1 million.

That number might seem daunting at first. But when you break it down into monthly contributions and long-term compounding, it becomes far more achievable.

In the early years, the focus should not be on dividends at all. It should be on growth.

By investing $300 each month and targeting an average return of 10% per year (not guaranteed), you are effectively building the engine that will later produce income.

At this stage, every dollar earned should be reinvested. Dividends, capital gains, everything goes back into the portfolio to accelerate growth.

Over time, this creates a compounding effect where your investments begin generating returns on top of returns.

Growing your portfolio

Compounding does not feel powerful at the beginning. But there comes a point where it starts to take over.

After 10 years, the portfolio may still feel modest. If everything goes to plan, it would sit at approximately $60,000 based on an average 10% annual return.

After 20 years, it starts to become meaningful and would have grown to almost $220,000.

But somewhere in the third decade, growth will accelerate quickly. So much so, after 30 years your portfolio would have grown to become $625,000.

After which, it would take just five more years to grow your portfolio to $1 million, all else equal.

Transitioning to income

Once the portfolio approaches a meaningful size, the strategy can begin to shift.

Instead of focusing purely on growth, you can gradually tilt toward income-producing Australian shares. This might include banks, infrastructure companies, and other reliable dividend payers like Telstra Group Ltd (ASX: TLS) or Harvey Norman Holding Ltd (ASX: HVN).

At this stage, a 5% dividend yield is the target. On a $1 million portfolio, that equates to the $50,000 annual second income target.

Small changes, big impact

While $300 a month can get you there in 35 years, small adjustments can make a big difference.

Increasing your contributions over time, even slightly, can significantly shorten the journey.

Even an extra $50 or $100 a month, or occasional lump sum investments, can accelerate progress more than most people expect.

For example, $500 a month instead of $300 a month would take 30 years (based on a 10% per annum return) to reach $1 million.

It is a long game

This strategy is not about quick wins or short-term gains.

It is about building something gradually, almost quietly, until one day it becomes meaningful.

A $50,000 annual second income from Australian shares does not come from one great investment. It comes from hundreds of small, consistent decisions made over time. And it all starts with that first $300.

The post How to invest $300 a month in Australian shares to target a $50,000 annual second income appeared first on The Motley Fool Australia.

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Motley Fool contributor James Mickleboro 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 positions in and has recommended Harvey Norman and Telstra Group. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Scott Phillips.