"How much do I need to retire?" is the biggest financial question most people never actually calculate. They save vaguely, hope it is enough, and only find out too late that it is not. The good news is that a solid estimate needs just a few inputs — your desired annual spending, inflation, and how long the money must last — and some simple rules turn those into a target. This guide walks through the method for Indian conditions and shows how regular investing builds the corpus.
Start with your spending, not your income
Retirement planning begins with one number: how much you will spend each year once you stop working. Many costs fall in retirement — you are no longer saving for retirement, the home loan may be paid off, and children are independent — but others, especially healthcare, rise. A common starting assumption is that you will need around 70–80% of your pre-retirement expenses, but the honest approach is to build it from your actual expected costs. Everything else in the calculation flows from this figure, so it is worth getting right.
The 4% rule
The most widely used shortcut for turning annual spending into a corpus is the 4% rule. It says that if you withdraw about 4% of your retirement savings in the first year and adjust that amount for inflation each year after, the corpus should last roughly 30 years. Flip it around and it gives a simple target:
Corpus needed = Annual expenses × 25
So if you will spend ₹6 lakh a year in today's terms, the rule suggests a corpus of about ₹1.5 crore. The "×25" is just the inverse of 4%. It is a starting estimate rather than a guarantee — many Indian planners prefer a more conservative 3–3.5% withdrawal (a multiple of 28–33×) given long lifespans and market uncertainty — but it anchors the target usefully.
The inflation trap
Here is the mistake that wrecks retirement plans: calculating the corpus in today's rupees. If you are 30 and retire at 60, three decades of inflation will hugely inflate your future costs. At 6% inflation, something costing ₹6 lakh a year today will cost roughly ₹34 lakh a year in 30 years — so the corpus you need is far larger than today's figure suggests. And inflation does not stop at retirement; your withdrawals must keep rising through a 25–30 year retirement, which is exactly why the 4% rule builds in annual inflation adjustments. Always work in future rupees. The Retirement Calculator handles this, projecting your future expenses and the corpus required to fund them.
Don't underestimate longevity
People consistently plan for too short a retirement. With rising life expectancy, someone retiring at 60 may well live to 85 or beyond — a 25-to-30-year retirement to fund, entirely without a salary. Underestimating this is dangerous, because running out of money at 80 leaves no way to recover. It is safer to plan for a long life and a slightly lower withdrawal rate; the cost of over-saving a little is minor next to the cost of falling short.
Keep some money growing
A retirement corpus should not all sit in fixed deposits. If your entire savings earn a low, taxable return while inflation runs at 6%, the real value erodes every year. A sensible retirement portfolio keeps a portion in equity even after you retire — enough to outpace inflation over the long run — while holding several years of expenses in safe, liquid instruments so you never have to sell equity in a downturn. This balance lets the growth engine keep running while protecting near-term spending.
How to build the corpus
A crore-plus corpus sounds daunting, but compounding over a long horizon makes it achievable with disciplined monthly investing — and the earlier you start, the smaller the monthly amount needs to be. A modest SIP begun in your twenties can reach the same target as a much larger one begun in your forties, because the early money compounds the longest. See what monthly investment reaches your goal with the SIP Calculator. Combine growth assets with tax-efficient vehicles: the PPF Calculator shows tax-free long-term compounding for the safer slice, and the NPS Calculator projects a pension corpus with its extra tax deduction under 80CCD(1B).
Account for other income sources
Your corpus does not have to cover every rupee of retirement spending on its own — other income streams reduce the amount you must accumulate. A rental property, an annuity or pension, EPF and NPS payouts, and even part-time work in early retirement all offset your withdrawals. If you expect, say, ₹15,000 a month from a pension and rent, your corpus only needs to fund the gap between that and your total expenses. Map out every expected source before fixing your target, but be conservative: treat uncertain income (like part-time work you may not want to do at 75) as a bonus rather than a pillar. The corpus should comfortably cover your essential spending even if the optional income never materialises.
Review it regularly
A retirement plan is not set once. Your expenses, income, inflation expectations and returns all change, so revisit the numbers every year or two and adjust your monthly investment accordingly. Stepping up your SIP whenever your salary rises is one of the most effective ways to stay on track without feeling the pinch. The goal is not a single perfect calculation but a habit of checking that you are still heading towards a corpus that will comfortably outlast you. Treat any windfalls along the way — a bonus, a gratuity payout, an inheritance — as opportunities to top up the corpus rather than upgrade your lifestyle, and you will reach the target sooner and with more margin for the surprises a long retirement inevitably brings.
Key takeaways
- Start from your expected annual spending in retirement, not your current income.
- The 4% rule gives a rough target of annual expenses × 25 (be more conservative for long lives).
- Calculate in future, inflation-adjusted rupees — today's figures badly understate the need.
- Plan for 25–30 years, keep part of the corpus in growth assets, and build it with early, regular SIPs.