🔥InflectionFI

Coast, Lean and Barista FIRE (UK)

FIRE (Financial Independence, Retire Early) comes in flavours that trade off how much you save, how much you'll spend, and whether you keep working part-time. Lean FIRE means a low-cost retirement (a smaller pot, tighter spending); Fat FIRE a higher-spending one; Coast FIRE means you've saved enough that it will grow into your target without adding more; and Barista FIRE means part-time or lower-stress work covers some spending while your pot keeps growing. Each implies a different number and a different withdrawal rate.

The flavours, briefly

Standard FIRE: a pot of ~25× your spending (a 4% withdrawal rate). Lean FIRE: the same idea on a lower budget, often with a more cautious ~3.25% rate. Fat FIRE: a larger pot for a higher-spending lifestyle. Coast FIRE: you stop adding to investments and let compounding carry them to your target by your chosen retirement age — you only need to cover current spending until then. Barista FIRE: part-time income bridges the gap, so you need less invested up front and can retire from full-time work sooner.

Which fits the UK picture

Barista and Coast FIRE fit UK early retirement especially well, because the hardest part is the bridge to pension access at 57 — part-time income or a partly-grown pot can cover exactly those gap years without needing a huge accessible pot. The calculator supports each type (it sets the withdrawal rate to match) and models part-time income where it actually helps: in the bridge and year-by-year projection.

Model your own numbers — ISA/SIPP split, the bridge to 57, Monte Carlo and more.

Open the free UK FIRE calculator →

Frequently asked questions

What is Coast FIRE?

You have invested enough that, with no further contributions, compounding alone should reach your retirement target by your chosen age. Until then you only need to cover your current spending.

What is Barista FIRE?

Semi-retirement where part-time or lower-stress work covers some of your spending while your investments keep growing — so you need a smaller pot to leave full-time work.

What is the difference between Lean and Fat FIRE?

Lean FIRE is a lower-cost retirement on a smaller pot (often a more conservative withdrawal rate); Fat FIRE funds a higher-spending lifestyle and therefore needs a larger pot.

Coast FIRE calculatorWork out your UK Coast FIRE number — the pot that grows to your retirement target with no further saving. UK safe withdrawal rateWhat a safe withdrawal rate means for UK early retirement — where the 4% rule comes from, why UK early retirees often use 3.25–4%, and how tax and a long retirement change it. How much to retire?How much you need to retire in the UK, by target income — computed with UK tax on withdrawals.

InflectionFI is an educational planning tool, not financial or tax advice. Figures are estimates based on your inputs and stated assumptions. Verify your situation with a qualified adviser.