The 4% Rule Abroad: Does It Still Work in a Different Currency?
A rule built for one currency and one cost of living doesn’t automatically survive the move to another.
The 4% rule gets quoted constantly in retirement planning circles: withdraw 4% of your portfolio in year one, adjust for inflation each year after, and — on the numbers behind the original research — your money should comfortably outlast a 30-year retirement.
It’s a genuinely useful starting point. The trouble is that it was built and tested almost entirely on US market data and US spending patterns. Retire in Vietnam, Thailand or Malaysia, funded by a pension or portfolio in sterling, dollars or Australian dollars, and two of the rule’s core assumptions stop holding quite so neatly.
The first problem: you’re spending in a currency you’re not earning
The 4% rule assumes your spending and your portfolio move in the same currency, more or less in step with each other. Once you’re drawing a UK pension to cover costs priced in Vietnamese dong, that assumption breaks. Your withdrawal might be a steady £2,000 a month on paper, but what that actually buys locally shifts with the exchange rate — sometimes generously, sometimes not.
Most people notice this the first time a strong month for sterling makes the month’s shopping feel almost free, and a weak month makes it feel tight for no reason they did anything differently. That volatility isn’t in the original 4% modelling at all.
The second problem: your actual cost of living is lower — which changes the maths in your favour
Here’s the part that tends to get missed in the “does the 4% rule still work” debate: for most people retiring to Southeast Asia, the honest answer is that the rule doesn’t need to work as hard, because the number it’s being asked to produce each month is often meaningfully smaller than it would be at home.
A withdrawal rate that felt tight covering costs in the UK, US or Australia frequently has real breathing room once it’s covering costs in Vietnam or Thailand instead. That’s not a reason to abandon the discipline — it’s a reason some people can safely consider a slightly higher initial withdrawal rate, or build in more of a buffer, once the numbers are run properly for their actual situation.
“The 4% rule was never wrong. It was just built for a cost of living most people retiring to Southeast Asia no longer have.”
Whether your own number should sit above, below, or right at 4% depends entirely on your currency mix, your spending pattern, and how much of a buffer you want against a bad exchange rate year. That’s exactly what a proper cash flow model is for — happy to run yours on a free Discovery Call.
What actually matters more than the percentage
In practice, the specific number — 3.5%, 4%, 4.5% — matters less than three things most people don’t think about until someone points them out:
Currency hedging or a cash buffer. Holding a year or two of spending in the currency you actually spend in smooths out the exchange rate swings that the original 4% rule never had to account for.
Where the withdrawal actually comes from. Drawing from a pension, an ISA, a pension drawdown, and cash savings all carry different tax and timing consequences depending on which country’s rules apply to each pot.
Reviewing annually, not assuming. A rate that made sense at 60 with sterling strong might need adjusting at 65 with sterling weak. The rule is a starting point for the conversation, not a number you set once and leave alone for thirty years.
None of this means the 4% rule is the wrong tool. It just means using it abroad requires one extra layer of thinking that most of the articles quoting it never mention.
Want to know what your actual, currency-adjusted withdrawal rate should be?