Why Your Withdrawal Rate Matters More Than Your Corpus
"How much do I need?" is the wrong first question.
The wrong question
Ask anyone planning for retirement and they will give you a number. ₹5 crore. ₹10 crore. The number varies. The framing never does: "I need X to retire."
But a corpus is not a plan. ₹5 crore can last 12 years or 40 years. The difference is not how much you have — it is how much you take out each year.
The right question
The better question is: at what rate can I withdraw from my corpus each year, such that I do not run out before I die?
This is the withdrawal rate. It is the single most important number in retirement planning, and most people never think about it.
The 4% rule
In 1994, financial planner William Bengen studied US market data going back to 1926. He found that retirees who withdrew 4% of their portfolio in year one — and adjusted that amount for inflation each year — never ran out of money over a 30-year retirement.
The "4% rule" became gospel. And it is a useful starting point. But it has limits.
A rule derived from US equities over a specific period is a heuristic, not a law.
Indian markets have different return profiles. Inflation behaves differently. Healthcare costs scale differently. The 4% rule tells you where to start thinking — not where to stop.
The math that matters
Consider two scenarios:
Scenario A: ₹5 crore corpus, 6% annual withdrawal (₹30 lakh/year). If the corpus earns 8% and inflation is 6%, this money runs out in roughly 18 years.
Scenario B: ₹3 crore corpus, 3% annual withdrawal (₹9 lakh/year). Same return and inflation assumptions. This money lasts effectively forever — the withdrawals never exceed the real growth.
A smaller corpus with a lower withdrawal rate outlasts a larger corpus with a higher one. The rate is the lever.
Perpetual withdrawal
There is an elegant idea buried in the math: if your withdrawal rate is at or below your real rate of return, your corpus never depletes. You live off the interest and the principal stays intact.
This is not just theoretical comfort. It means you can plan for uncertainty. If you do not know how long you will live — and none of us do — a perpetual withdrawal strategy removes the scariest variable from the equation.
Model it, don't guess
The FIRE Calculator has a SWP section that models exactly this. Plug in your expected corpus, withdrawal rate, and inflation. See when the money runs out — or if it does not. Adjust until you find the rate that lets you sleep at night.