Investment20 March 2026 · 7 min read

FIRE Calculator: How to Calculate Your Financial

What is the FIRE movement, how to calculate your FI number using the 4% rule, FIRE variants (Lean FIRE, Fat FIRE, Barista FIRE), and a step-by-step guide.

FIRE stands for Financial Independence, Retire Early. The movement is built on a simple principle: save and invest aggressively, reach a target corpus, and live off the returns — potentially retiring decades before the traditional age of 60–65.

The 4% Rule: Foundation of FIRE

The 4% rule (from the Trinity Study, 1998) states that you can withdraw 4% of your portfolio each year for at least 30 years without running out of money — assuming a diversified equity/bond portfolio.

Your FIRE Number

FIRE Number = Annual Expenses × 25

This is simply the inverse of the 4% rule. If you need ₹10 lakhs/year to live, you need a corpus of ₹2.5 crore. At 4% withdrawal, ₹2.5 crore × 4% = ₹10 lakhs per year.

FIRE Variants

TypeAnnual ExpensesLifestyle
Lean FIRE₹4–6 lakhs/yearMinimal, frugal lifestyle
Regular FIRE₹8–15 lakhs/yearComfortable middle-class
Fat FIRE₹25+ lakhs/yearLuxury, no compromises
Barista FIREPartial retirementPart-time work covers basics, portfolio covers rest
Coast FIREStop investing nowCurrent investments coast to retirement goal without more contributions

How Long Will It Take?

Your FIRE timeline depends almost entirely on your savings rate — not your income.

Savings RateYears to FIRE
10%~43 years
25%~32 years
50%~17 years
70%~9 years
90%~3 years

Assumes 7% real return (after inflation) and spending the rest in retirement.

The India-Specific FIRE Calculation

For Indian FIRE seekers, adjust for:

  • Inflation: India's CPI inflation averages 5–6%. Your corpus needs to beat this.
  • Healthcare: No universal healthcare — budget ₹5–10 lakhs/year in retirement for health insurance and out-of-pocket costs.
  • Withdrawal rate: Many Indian planners recommend 3–3.5% withdrawal rate given longer life expectancy and higher inflation.
  • Tax: Equity portfolio withdrawals attract 12.5% LTCG above ₹1.25 lakhs.

Step-by-Step: Building Your FIRE Plan

  1. Track all expenses for 3 months to get your annual spending baseline.
  2. Multiply by 25 (or 33 for a 3% withdrawal rate) to get your FIRE number.
  3. Calculate your current net worth (investable assets only, not your home).
  4. Determine how much to invest monthly to bridge the gap within your target timeline.
  5. Optimise: increase income, reduce expenses, or both.

Calculate exactly when you can retire with our FIRE Calculator.

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