Fat FIRE, Lean FIRE, Coast FIRE, Barista FIRE — Defined
The four variants of FIRE, what they mean, how the math works for each, and what the numbers look like with Indian costs.
The Four Variants
FIRE (Financial Independence, Retire Early) has four commonly discussed variants. They differ on two axes: target expense level and whether you stop earning entirely.
| Variant | What It Means | You Stop Working? |
|---|---|---|
| Lean FIRE | Cover essentials only | Yes |
| Fat FIRE | Maintain current urban lifestyle | Yes |
| Coast FIRE | Invest enough early, let compounding finish the job | No — but you stop saving |
| Barista FIRE | Portfolio covers part of expenses, part-time work covers the rest | Partially |
All four use the same formula: FIRE Number = Annual Expenses × Multiplier
The multiplier depends on the withdrawal rate. At 4% (the US-origin Trinity Study rate), it’s 25x. At 3% (commonly discussed for India given higher inflation), it’s 33x.
Lean FIRE
Covers essentials. Typical profile: Tier-2/3 city, no car, minimal discretionary spending.
| Category | Monthly |
|---|---|
| Housing (2BHK, Tier-2 city) | ₹12,000 |
| Groceries & household | ₹8,000 |
| Utilities & phone | ₹3,000 |
| Transportation | ₹3,000 |
| Health insurance | ₹4,000 |
| Discretionary | ₹5,000 |
| Total | ₹35,000 |
| Multiplier | Corpus Required |
|---|---|
| 25x (4%) | ₹1.05 Cr |
| 33x (3%) | ₹1.39 Cr |
Key characteristic: Fastest to reach. No margin for large unexpected expenses or lifestyle changes.
Fat FIRE
Maintains a full urban lifestyle — metro housing, car, children’s education, travel, dining.
| Category | Monthly |
|---|---|
| Housing (3BHK, metro) | ₹45,000 |
| Groceries & household | ₹18,000 |
| Children’s education | ₹25,000 |
| Transportation (car) | ₹15,000 |
| Utilities & phone | ₹6,000 |
| Dining & entertainment | ₹15,000 |
| Health insurance + medical | ₹10,000 |
| Travel (amortised) | ₹15,000 |
| Domestic help | ₹6,000 |
| Discretionary | ₹15,000 |
| Total | ₹1,70,000 |
| Multiplier | Corpus Required |
|---|---|
| 25x (4%) | ₹5.10 Cr |
| 33x (3%) | ₹6.73 Cr |
Key characteristic: Largest corpus. Accumulation period is typically 18–22+ years even for high earners.
Coast FIRE
The idea: invest a lump sum early, then let compounding grow it to a full retirement corpus by 55–60. After hitting the “coast number,” you only need to earn enough to cover current expenses — no more saving required.
Coast Number by Age
Target: ₹4 Cr by age 55. Assumed CAGR: 12.2% (Nifty 50 15-year average, BMS Money).
| Your Age | Years to 55 | Coast Number |
|---|---|---|
| 25 | 30 | ₹12.5L |
| 28 | 27 | ₹17.5L |
| 30 | 25 | ₹22L |
| 35 | 20 | ₹40L |
| 40 | 15 | ₹71L |
Sensitivity to Return Assumptions
The coast number shifts significantly with return assumptions:
| Assumed CAGR | Coast Number at Age 28 (to reach ₹4 Cr at 55) |
|---|---|
| 10% | ₹30.5L |
| 12% | ₹18.8L |
| 14% | ₹11.6L |
A 2% change in assumed returns shifts the coast number by ~35–40%.
Key characteristic: You don’t retire early. You stop saving early. Sensitive to actual returns deviating from assumed returns — sequence of returns risk applies.
Barista FIRE
Portfolio covers a portion of expenses. Part-time or freelance income covers the rest.
How the Math Changes
₹1L/month total expenses. Part-time income covers a portion. Portfolio covers the rest.
| Part-Time Income | Portfolio Must Cover | Corpus at 33x |
|---|---|---|
| ₹0 (full FIRE) | ₹12L/year | ₹3.96 Cr |
| ₹25K/month | ₹9L/year | ₹2.97 Cr |
| ₹35K/month | ₹7.8L/year | ₹2.57 Cr |
| ₹50K/month | ₹6L/year | ₹1.98 Cr |
Each ₹10K/month of part-time income reduces the required corpus by ~₹40L.
Key characteristic: Lower corpus target. Depends on continued ability to earn part-time income.
Comparison
| Lean | Fat | Coast | Barista | |
|---|---|---|---|---|
| Monthly expenses | ₹35K | ₹1.7L | Varies | ₹1L |
| Corpus needed (33x) | ₹1.4 Cr | ₹6.7 Cr | ₹12–71L (one-time) | ₹2–3 Cr |
| Stop working entirely | Yes | Yes | No (stop saving) | No (part-time) |
| Income after FIRE | ₹0 | ₹0 | Covers expenses only | ₹25–50K/month |
| Location dependency | High (needs low-cost area) | Low | Low | Low |
Variables That Shift These Numbers
All the numbers above assume static expenses. In practice:
- India’s CPI inflation averaged 5.4% (2014–2024) per World Bank
- Healthcare inflation: 14% in 2024 (ACKO)
- Education inflation: 8–12% (BankBazaar)
Different expense categories inflate at different rates, which means FIRE numbers in today’s rupees diverge from FIRE numbers in future rupees depending on expense composition.
WealthSim lets you model each expense category with its own inflation rate and project your net worth year by year for any of these FIRE variants. Try it at app.wealthsim.in.