Where a US tech worker can actually afford to retire

The headline

On the classic 25× rule (a 4% safe withdrawal rate), the nest egg a comfortable single-person retirement requires swings by $1.2M–$1.8M depending only on where you live:

• A tech worker with $800K saved isn't retirement-ready in San Francisco — but is fully financially independent today in Lisbon, Valencia, Mexico City, or Athens.
• You don't even have to leave the country: Raleigh or Austin alone cut a Bay Area number by $0.9M–$1.2M.

For an industry where a mid-career engineer can save hard but watch the Bay Area swallow it, geography is the highest-leverage retirement lever there is — bigger than one more grinding year, bigger than market timing.

The Index — what you need to retire, by city

Comfortable living cost for one person (rent + essentials), and the nest egg it implies at a 4% withdrawal rate. Personal healthcare — especially pre-Medicare in the US — is on top; the app adds it for your real number.

City	Cost/mo (USD)	Nest egg (25×)	vs San Francisco
Goa, India	$717	$215K	$1.82M less
Chiang Mai, Thailand	$864	$259K	$1.78M less
Da Nang, Vietnam	$1,055	$317K	$1.72M less
Medellín, Colombia	$1,294	$388K	$1.65M less
Kuala Lumpur, Malaysia	$1,397	$419K	$1.62M less
Mérida, Mexico	$1,585	$475K	$1.56M less
Porto, Portugal	$2,065	$620K	$1.42M less
Valencia, Spain	$2,228	$668K	$1.37M less
Mexico City, Mexico	$2,486	$746K	$1.29M less
Lisbon, Portugal	$2,554	$766K	$1.27M less
Athens, Greece	$2,554	$766K	$1.27M less
Madrid, Spain	$2,772	$832K	$1.21M less
Raleigh, USA	$3,650	$1.10M	$945K less
Austin, USA	$3,650	$1.10M	$945K less
San Francisco, USA	$6,800	$2.04M	—

Does the 25× rule work at any age?

Short answer: no — and that's the honest catch buried in every "you need 25× to retire" headline. The 25× rule comes from the 4% rule, which assumes a roughly 30-year retirement. Retire earlier and your money has to stretch further, so a safe withdrawal rate drops and your number goes up. Retire later, with a shorter horizon, and you can safely draw more, so your number comes down.

Here's the same comfortable life in Lisbon (about $30,600/yr) at three ages:

If you retire at…	Retirement length	Safe withdrawal	Multiplier	Lisbon number
40 (early FIRE)	~50 years	~3.3%	30×	$919K
60	~30 years	4.0%	25×	$766K
70	~20 years	~5.0%	20×	$613K

The Index above uses 25× as a midpoint, but your real number also shifts with how much guaranteed income you'll have (Social Security, a pension), market valuations the year you retire, and how flexible your spending is. A single multiplier can't capture any of that — which is why a flat rule is a starting point, not an answer.

This is the gap Khyren Horizon fills. Instead of one multiplier, it runs a Monte Carlo simulation over your retirement length and thousands of market scenarios — including bad ones early, the "sequence-of-returns" risk that quietly sinks early retirees — alongside your income sources, home equity, and phase-aware healthcare, and reports the probability your money actually lasts. That's a number you can act on.

What this means for a tech career

• The "one more year" trap is often a "wrong city" problem. Engineers delay retirement to hit a Bay Area number a move makes irrelevant overnight.
• A layoff can be a head start, not a setback — if your number is built around where you'll actually live.
• RSUs and a remote-friendly skillset travel. Many of these destinations have digital-nomad and retirement visas built for exactly this.

Cost of living is only half the math. Here's what a "cheapest places to retire" list skips — and what actually moves your number:

• Taxes. US citizens are taxed on worldwide income; some countries pile on local tax, others offer retiree tax breaks. Where you land changes your real spending power.
• Healthcare before Medicare. Retire before 65 and you self-fund health insurance — often the single biggest pre-Medicare cost, and wildly different abroad.
• Sequence-of-returns risk. A market crash in your first few retirement years does far more damage than the same crash later. A flat 4% ignores this; a simulation doesn't.
• Currency and inflation. If you save in dollars but spend in euros or baht, exchange-rate swings move your number — and local inflation compounds over decades.