Guide

How much do you really need to retire early?

By Kenneth Bonnici, who retired at 53 · 5 min read

There is no single number. Anyone who hands you one is selling a rule of thumb, and rules of thumb are built to keep you working, not to set you free. The honest answer is this: you have enough when your money outlasts you, given how you spend, what you own, and when you stop. This guide shows you how to find that point, and why the popular shortcuts get early retirement wrong.

The 4% rule, and why it fails the people who need it most

The 4% rule says you can retire once you have twenty-five times your annual spending invested, then draw down 4% a year. It is neat, memorable, and repeated so often that most people accept it without ever asking where it came from or whether it fits their life.

It doesn't. The rule was built to answer one narrow question: what withdrawal rate almost never runs out over thirty years? That is a fine question if your only fear is going broke. It is the wrong question if what you actually want is to stop working as early as you sensibly can and spend your best years living.

Follow it faithfully and the likeliest outcome isn't ruin, it's the opposite. You die with a large pile of money you never spent, bought with years of your life you can't get back. The rule optimises for "don't run out". It says nothing about "have enough to retire early and live the life you've earned". Those are different targets, and the gap between them can be a decade of freedom.

It is also a shortcut for people who would rather not do the work. Thirty to sixty minutes on a proper cash-flow projection of your actual life will tell you far more than a rule someone invented for an average person who isn't you. And here is the irony: the people who lean on the rule of thumb rarely trust it enough to act on it anyway, so they never retire early regardless. If you are reading this, you are probably not the type to hand your most important decision to a slogan.

The real question is not "what's my number", it's "does my money last?"

The trouble with a single number is that it is a snapshot, and retirement is a film that runs for thirty, forty, fifty years. Your spending changes. Pensions and state benefits arrive years after you stop. You might sell a house, help a child, take one big trip a year. A fixed multiple of today's spending can't hold any of that.

A projection can. Instead of "what lump sum do I need", it asks the question that matters: run my real life forward, year by year, and does the money last? Feed in your spending, assets, income, pensions and their start dates, and the one-off events you can foresee, and let it play out. The answer isn't a number to hit. It's an age: the earliest point at which the projection still holds all the way to the end.

That is what Enough to Quit does. It is the model I built for myself, because I couldn't find one honest enough to trust.

What actually decides your number

A handful of things move the answer far more than the raw size of your portfolio:

• What you spend. The biggest lever by far. Every £1,000 a year you don't need is roughly £25,000 you never have to accumulate.
• When you stop. Retire earlier and your own savings and income do the heavy lifting for longer, before any pension arrives to help.
• Your income and asset mix. Rental income, a partner still working, a portfolio, a property you could sell: each one reshapes the whole projection.
• The big one-off events. Selling a home, a child's education or wedding, a house move, a windfall, the trip you've always promised yourself: a single large event can swing the answer more than a year of market returns.
• Your safety margin. A cash buffer and a sensible reserve are what let you retire with confidence rather than a spreadsheet full of hope.

A worked example

The hard part isn't the money. It's knowing.

Here is the thing almost nobody tells you: the hardest part of early retirement isn't having enough money. It's knowing that you do.

I meet people wealthier than me all the time who have no time to do anything but work. They're stuck in the same routines, quietly yearning for freedom, not realising they are already free. They have more than enough. What they lack is the one calculation that would let them believe it, and so they never begin.

The real cost of not knowing is not money. It is time.

I was nearly one of them. I retired at 53, and I'm glad I did. But if I'd found the courage to run this projection a few years earlier, I would very likely have retired a couple of years sooner.

Find your number

You can get a first answer in about thirty seconds, and a serious one in about thirty minutes. Don't take a stranger's rule of thumb for the most important financial decision of your life. Run your actual numbers.

See if you can quit →

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Further reading: the best money and early-retirement books, blogs and tools.

Educational information only, not financial advice. ETQ produces illustrative model output that is sensitive to your inputs and the tool's default assumptions. Speak to a qualified professional before acting on a projection.