How much would an investor need in an ISA for a £999 monthly passive income?

Harvey Jones does some simple maths to show how a regular monthly investment of £250 might one day deliver a superb passive income of almost £1,000 a month.

| More on:

The content of this article was relevant at the time of publishing. Circumstances change continuously and caution should therefore be exercised when relying upon any content contained within this article.

Businessman using pen drawing line for increasing arrow from 2024 to 2025

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.

Investors seeking passive income from FTSE 100 shares might wonder how much they need to secure a comfortable retirement. So let’s crunch the numbers.

Generating a second income target of £999 a month would deliver annual income of £11,988 a year. That would almost double the full new State Pension, so it’s well worth having.

The amount of capital required to generate that income would depend on the yield of the investor’s portfolio.

I believe it’s realistic to aim for an average yield of 6% from a diversified mix of FTSE 100 dividend shares. With that assumption, someone would need a total of £199,800 invested to hit their goal.

Building retirement on FTSE 100 shares

That’s a large sum, but it can be built up over time. Someone investing £250 a month could reach this milestone in 25 years, assuming an average total return of 7% per year. That’s roughly in line with the long-term FTSE 100 average total return, which combines both capital growth and dividend reinvestment.

To illustrate the kind of shares that could help build this income stream, let’s look at Aviva (LSE: AV.).

While some FTSE financials have struggled in recent years, as one of the UK’s largest insurers Aviva has delivered solid performance.

The stock has climbed 16% over the last year and is up a hugely impressive 63% over five years.

That’s just the share price growth. Investors have also received bags of dividends over that period, with the trailing yield currently an impressive 6.67%. The total return must be comfortably above 100% in that time.

Avvia shares now look a little expensive, with a price-to-earnings (P/E) ratio of 22.7. However, given the company’s impressive performance and growing profitability, markets believe it’s justified.

The Aviva share price may slow from here

That said, Aviva shares won’t always climb at this pace and dividends aren’t guaranteed. Today’s stock market volatility could potentially hit the value of the assets it holds to offset insurance risks, and hit inflows into its investing division. Once reflected in results, investor enthusiasm may cool.

However, I still think it has a valuable role to play in a well-structured portfolio.

While Aviva is a strong candidate to consider, relying on just one or two stocks is risky. Income seekers should look to hold around 15 to 20 dividend shares in total. Stocks from sectors like utilities, consumer goods and pharmaceuticals can help balance out market fluctuations.

By holding a mix of these types of businesses, investors can build a portfolio that generates reliable passive income while reducing exposure to the risks of individual stocks.

Generating £999 a month in passive income is achievable with a patient, long-term approach. With luck it should rise over time, as companies increase shareholder payouts.

Our investor shouldn’t just stick to tucking away £250 a month though. They should aim to increase that in time to reflect inflation, and throw in lump sums when they have cash to share.

The more they invest, the greater their potentail financial freedom in retirement. That’s the magic of compounding and the joy of passive income.

Harvey Jones has no position in any of the shares mentioned. The Motley Fool UK has no position in any of the shares mentioned. Views expressed on the companies mentioned in this article are those of the writer and therefore may differ from the official recommendations we make in our subscription services such as Share Advisor, Hidden Winners and Pro. Here at The Motley Fool we believe that considering a diverse range of insights makes us better investors.

More on Investing Articles

Road 2025 to 2032 new year direction concept
Investing Articles

My favourite FTSE value stock falls another 6% on today’s results – should I buy more?

Harvey Jones highlights a FTSE 100 value stock that he used to consider boring, but has been surprisingly volatile lately.…

Read more »

UK supporters with flag
Investing Articles

See what £10,000 invested in the FTSE 100 at the start of 2025 is worth today…

Harvey Jones is thrilled by the stunning performance of the FTSE 100, but says he's having a lot more fun…

Read more »

Investing Articles

Prediction: here’s where the latest forecasts show the Vodafone share price going next

With the Vodafone turnaround strategy progressing, strong cash flow forecasts could be the key share price driver for the next…

Read more »

Front view of a young couple walking down terraced Street in Whitley Bay in the north-east of England they are heading into the town centre and deciding which shops to go to they are also holding hands and carrying bags over their shoulders.
Investing Articles

How much do you need in a SIPP or ISA to aim for a £2,500 monthly pension income?

Harvey Jones says many investors overlook the value of a SIPP in building a second income for later life, and…

Read more »

Friends at the bay near the village of Diabaig on the side of Loch Torridon in Wester Ross, Scotland. They are taking a break from their bike ride to relax and chat. They are laughing together.
Investing Articles

Can you turn your Stocks and Shares ISA into a lean, mean passive income machine?

Harvey Jones shows investors how they can use their Stocks and Shares ISA to generate high, rising and reliable dividends…

Read more »

Close-up image depicting a woman in her 70s taking British bank notes from her colourful leather wallet.
Investing Articles

Move over Lloyds, are Barclays shares the ones to go for in 2026?

As we head into 2026 with inflation and interest rates set to fall, what does the banking outlook offer for…

Read more »

Young Black man sat in front of laptop while wearing headphones
Investing Articles

Down 60% with a 10.2% yield and P/E of 13.5! Is this FTSE 250 stock a once-in-a-decade bargain? 

Harvey Jones is dazzled by the yield available from this FTSE 250 company, and wonders if it's the kind of…

Read more »

Shot of a senior man drinking coffee and looking thoughtfully out of a window
Dividend Shares

How much do you need in the stock market to target a £3,500 monthly passive income?

Targeting extra income by investing in the stock market isn't just a pipe dream, it can be highly lucrative. Here's…

Read more »