How to use this tool
Select a city — the tool pre-fills a conservative annual spending estimate for a single person living comfortably (not austerely) in that location as of 2025–2026. Adjust the annual spend figure to reflect your personal lifestyle. Set your withdrawal rate — the default is 4%, the classic “safe withdrawal rate” discussed below. The tool then shows you the total nest-egg you’d need in USD, and translates that into sats at three price scenarios: today’s BTC price, 2× today’s price, and 5× today’s price.
The three-scenario display is deliberate. Bitcoin’s future price is unknown. Rather than pretend one number is correct, the tool shows you a range: how many sats do you need if Bitcoin stays at its current price, if it doubles, or if it grows fivefold? This framing makes the uncertainty explicit rather than hiding it behind a single optimistic or pessimistic assumption.
The safe withdrawal rate (and its limitations)
The 4% withdrawal rate comes from the Trinity Study, a 1998 academic paper by three finance professors at Trinity University. They analyzed historical US stock and bond portfolios and found that a 4% annual withdrawal from a balanced portfolio had not depleted over any historical 30-year period. This became the canonical “safe withdrawal rate” in personal finance.
What the 4% rule actually says: If you retire with a balanced portfolio, withdraw no more than 4% in the first year, and adjust that dollar amount for inflation each subsequent year, you have historically not run out of money over a 30-year retirement.
What it does not say:
- It was calibrated to US market history from 1926–1995. Different periods, different markets, and different asset classes produce different conclusions.
- It assumes a 30-year retirement. Retire early at 35 and you might need 50+ years of coverage — the 4% rule becomes more precarious over longer horizons.
- It was developed for stock-and-bond portfolios, not Bitcoin. Bitcoin’s return history is very short, its volatility is extreme, and applying the Trinity Study’s methodology to a Bitcoin-only portfolio would require far more research than has been done.
- Sequence-of-returns risk matters enormously. A bear market in the first years of retirement is far more damaging than one in the middle or end, because early withdrawals deplete the principal permanently.
More recent research — including updates by the original Trinity Study authors — suggests that 3% to 3.5% may be more appropriate for long retirements or conservative investors, and that higher withdrawal rates are feasible only if you’re willing to reduce spending in down markets.
For this tool, the 4% default is a widely recognized convention, not a recommendation. Adjust it based on your situation. A 3% withdrawal rate is more conservative; 5% is more aggressive and carries meaningfully higher depletion risk.
City cost-of-living assumptions
The annual spending figures represent a conservative single-person budget: comfortable housing (not luxury), local transportation, groceries, dining out occasionally, healthcare, utilities, and some discretionary spending. They do not include:
- International health insurance (add $2,000–$8,000/year depending on age and coverage)
- Travel back to your home country
- Large one-time costs (home purchases, medical emergencies, major repairs)
- Supporting dependents
These figures are rough estimates based on available cost-of-living data as of 2025–2026. Actual costs vary significantly based on neighborhood, lifestyle, and local conditions. Bangkok’s Sukhumvit district costs far more than living in a Thai suburb. Lisbon’s historic neighborhoods are pricier than surrounding towns. The figures are starting points for thinking, not precise budgets.
Cheapest cities in the list:
- Chiang Mai, Thailand ($12,000/yr): Consistently ranked among the most affordable retirement destinations globally. Excellent food, high quality of life for the cost, and a large digital-nomad community. Climate is tropical; summers are hot.
- Bangkok, Thailand ($18,000/yr): More expensive than Chiang Mai but offers a massive city with world-class hospitals, international food scene, and excellent transport links.
- Mexico City, Mexico ($20,000/yr): Large, cosmopolitan, with fantastic food culture. Political and safety considerations vary by neighborhood.
Mid-range cities:
- Lisbon, Portugal ($24,000/yr): Popular among European and American retirees. EU access, good weather, and English widely spoken. Prices have risen significantly since 2020.
- Berlin, Germany ($32,000/yr): High quality of life, excellent healthcare, but housing costs have increased substantially.
- Buenos Aires, Argentina ($18,000/yr): Can be cheaper than this figure suggests due to the blue-dollar exchange rate; dollar-holders benefit from a favorable unofficial rate, but Argentina’s economic instability is a real risk.
Expensive cities:
- San Francisco and New York (US): Reflect the reality of US urban costs. At $84,000/year for San Francisco and $72,000 for New York, the nest-egg required is substantial — over $2 million at the 4% rule. These figures illustrate why geographical arbitrage is compelling for early retirees.
- Zurich, Switzerland ($78,000/yr): Switzerland consistently ranks as one of the most expensive countries globally. High wages, but also very high prices.
Why Bitcoin for retirement thinking
The case for denominating retirement goals in sats rests on several arguments, each with important caveats.
The deflationary thesis: Bitcoin’s supply is capped at 21 million, and new issuance halves roughly every four years. If demand for Bitcoin grows while supply is fixed, the purchasing power of each sat should increase over time — the opposite of how fiat currencies behave under central bank management. This thesis suggests that sats held today may buy more goods and services in the future than USD held today.
The caveats are significant: Bitcoin’s price has experienced drawdowns of 70–90% multiple times. A retiree withdrawing during a bear market faces brutal sequence-of-returns risk. At the 2022 low, Bitcoin had fallen 77% from its 2021 peak. A portfolio worth $2 million at peak was worth roughly $460,000 at trough. Anyone relying on that portfolio for $80,000/year in living expenses would have faced an immediate crisis.
What this means practically: If you plan to retire on Bitcoin, you need either:
- A much larger buffer (perhaps 10–20× annual expenses rather than 25× to hedge the volatility)
- A plan to convert Bitcoin to a more stable currency or assets as you approach retirement
- Income sources that don’t depend on Bitcoin’s price (rental income, work, traditional investments)
The most defensible approach: use Bitcoin as part of a diversified retirement portfolio, not the entirety of it. Treat your sats stack as the highest-upside, highest-risk component of your overall retirement savings — meaningful, but not the entire plan.
The price scenario columns explained
The three-column output shows sats needed at three BTC price assumptions:
Today’s price: How many sats you’d need if Bitcoin never increases in price. This is the conservative baseline — if Bitcoin appreciates at all, you’d need fewer sats than this column shows.
2× today’s price: If Bitcoin doubles from current levels before you retire or start withdrawing. Still conservative relative to Bitcoin’s historical trajectory, but a reasonable medium-term scenario.
5× today’s price: A bullish scenario. At 5× current prices, you need far fewer sats to reach the same USD nest-egg. This column illustrates the leverage effect of Bitcoin appreciation on your retirement target — every time Bitcoin’s price doubles, the required sats fall by half.
Note that these scenarios are symmetric: Bitcoin could also fall 50% or 80% before you retire. The tool only shows upside scenarios because the math is symmetric — if you’re concerned about downside, simply consider the “today’s price” column as the scenario where Bitcoin has already halved, and plan accordingly.
FAQ
Is 4% still valid today?
The research is contested. Some analysts argue that in a low-interest-rate environment (which characterized the 2010s), future expected returns are lower, making 4% too aggressive. Others point out that the 4% rule has a buffer — historically, most 30-year retirements ended with more money than they started with at 4%. For a first approximation, 4% is a reasonable starting point. For a long retirement (40+ years), consider 3% or lower.
Should I put my entire retirement in Bitcoin?
For most people, no. Bitcoin’s volatility creates enormous sequence-of-returns risk. A 70% drawdown in year one of retirement, combined with required withdrawals, can permanently impair a portfolio in ways that are difficult to recover from. A more conservative approach: stack sats during your working years, diversify as you approach retirement age, and maintain enough stable assets to cover 2–3 years of expenses at all times.
Which city should I pick?
The one you’d actually want to live in. Optimizing for the cheapest possible location often leads to poor quality of life and higher costs than expected once you account for travel, healthcare, and the social cost of distance from family and community. Pick a place that fits your lifestyle, then figure out the finances.
Are these cost-of-living figures accurate?
They are conservative estimates based on available data as of 2025–2026. Actual costs depend heavily on your specific choices. Housing in particular varies enormously within a single city. Use these as order-of-magnitude guidance, not precise budgets. Before retiring anywhere, spend at least a month there and track your actual spending.
What about taxes?
This tool ignores taxes entirely — a significant omission. Many countries tax foreign income, capital gains from Bitcoin sales, or charge substantial wealth taxes. Portugal’s NHR regime, Thailand’s territorial tax system, Argentina’s economic instability — each location has a different tax profile that could materially affect your effective annual cost. Consult a tax professional familiar with the specific country before making relocation decisions.
Sources:
- Trinity Study: Cooley, Hubbard & Walz (1998), “Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable” — AAII Journal
- Updated analysis: Pfau (2011), “Can We Predict the Sustainable Withdrawal Rate for New Retirees?” — Journal of Financial Planning
- Numbeo Cost of Living Index: numbeo.com
- Expatistan Cost of Living: expatistan.com