In our weekly series, readers can email in with any question about retirement and pension savings to be answered by our experts. If you have a question, email us at money@inews.co.uk.

Question: I am considering stopping work at the end of the year and will want instead to take an income from my self-invested personal pension. However, I don’t know how much I should be taking each month or year. I am conscious that I want to set a realistic level so that I don’t run out of money too fast. I have read something about a 4 per cent rule – but I don’t really understand what this is. Could you explain?

Answer: The benefit of building up a private pension pot is that it gives you more flexibility and choices to set an income to suit your needs in your later years. But working out how to convert that pot of money (and your other savings and investments) into an income – possibly to last a lifetime – can be a tricky decision.

You can access your pension pot from the age of 55 (rising to age 57 from 2028). You can take up to 25 per cent of the amount you take as tax-free cash and then take the remainder as a taxed lump sum, use it to buy an annuity (a guaranteed income for life), or move it into drawdown.
If you decide on a drawdown, you can set the income you take from the pot. This is completely flexible. You can decide on any figure you want, and you have the flexibility to change it at any time. You don’t have to take a regular income – it could be ad-hoc, or you could decide to stop or start at any time.

Often, people decide they want to use their pension pot to give them an income to last a particular amount of time, sometimes up to their death. The challenge then is deciding on the right rate to make sure the pot doesn’t run out of money before you reach the “end date”.

The “4 per cent rule” is one theory people have adopted to achieve this. It suggests people can withdraw up to 4 per cent of their drawdown pot each year, adjusted for inflation, and still expect their money to last 30 years.

This is a simple and easy rule to understand to estimate how much income you may want to take from your retirement savings. But of course, it’s not guaranteed to work, and landing on the right answer to the tricky question of how much money should I take is far more complicated.

As a starter, here are a few other things to consider.

The first thing to work out is how much money you need from your pension. This will depend on the other assets you have built up – such as ISAs and other savings – and when you plan on taking an income from them.

It will also depend on how much money you need in retirement and when. For example, you may anticipate having to contribute to a child’s wedding or helping them onto the property ladder.

But it’s not just about setting an amount. Inflation will erode the real value of your income over time, so factor in increases over time.

You also have to work out how long you need your money to last, and that will depend on your general health, life expectancy, and whether you want to leave any of your pot to pass on to other people, such as a partner or adult children.

You can also factor in market volatility. There are various tools around that can help you test what would happen to your savings if there were a market event – such as a significant fall.

A final thought. Whatever strategy and final figure you decide on, don’t ‘set and forget’. Instead, you will need to review this on a regular basis to take account of not only market changes to your remaining savings and investments, but also factors changing your income needs, such as inflation and changes in personal circumstances.

As you can see, there are many things to consider. If you don’t want to tackle this alone, a regulated financial adviser can help you understand your choices and can put together a financial plan for you based on cash-flow modelling to work out the best way to take your money over retirement.