How this FIRE calculator works
The engine simulates your corpus month by month. While you work, it grows at your pre-retirement return with your SIP added (stepped up yearly) while your expenses inflate. You reach FI when the corpus crosses your FIRE number — the withdrawal-rule multiple (25× to 40×) of your inflated annual expenses at that date. After retirement it simulates the drawdown: the corpus earns your post-retirement return while inflating expenses are withdrawn, and the calculator reports the age your money actually lasts till — the honest test of whether you can RE, not just FI.
Real vs nominal returns
A 12% return with 6% inflation is a (1.12/1.06 − 1) ≈ 5.7% real return — that's the number that grows your purchasing power. This calculator does all math in nominal terms with explicit inflation, then shows results in both then-₹ and today's ₹, so a ₹10 crore corpus 20 years out isn't mistaken for ₹10 crore of today's spending power.
Why 4% SWR may not fit India
The 4% rule comes from US market history with ~3% inflation. India's higher and more volatile inflation means many planners prefer 3–3.5% withdrawal (≈29–33× expenses). This calculator defaults to 3% but lets you choose — and the stress tests show what +2% inflation does to your plan.
FAQ
What's the difference between FI and RE?
FI is when your corpus crosses the target multiple of expenses. RE adds the harder question: will it survive 40+ years of withdrawals? The "corpus lasts till" line answers that with a full drawdown simulation, not a rule of thumb.
Should my SIP step up every year?
Yes if your income grows — a 5–10% annual step-up mirrors salary growth and can pull your FIRE age in by several years. Set it to 0 to model a flat SIP.
Which economy scenario should I use?
Plan on Base or Conservative and check that even Stagflation doesn't break you. If your FIRE age only works in the Optimistic scenario, it's a hope, not a plan.