Ask ten people how much they need to retire and you will get ten guesses, most of them far too low. The reason is simple: nobody retires on today’s expenses. A monthly spend of 60,000 rupees today becomes something very different after twenty-five years of inflation, and a retirement that lasts thirty years needs funding for all thirty. Calculating your retirement corpus is not guesswork – it is a short chain of arithmetic that anyone can follow. Here is the method, step by step, with a worked example you can adapt to your own numbers.

Step 1: Write down today’s annual expenses

Start with what you spend in a year, excluding expenses that will vanish by retirement – typically the home loan EMI if the house will be paid off, and children’s education costs. Include everything else: groceries, utilities, transport, insurance premiums, travel, medical costs and leisure. Suppose your current annual household expense is 7.2 lakh rupees, or 60,000 a month. Be honest here; underestimating this number is the single most common error in retirement planning, and it compounds through every later step. If you are unsure, track three months of spending and annualise it.

Step 2: Project those expenses to your retirement year

Money loses value every year, so you must grow today’s expenses by inflation for each year until you retire. The formula is simple: future expense equals current expense multiplied by (1 plus inflation rate) raised to the number of years. If you are 35 and plan to retire at 60, that is 25 years. At 6 per cent annual inflation – a reasonable long-term assumption for household expenses in India – 7.2 lakh rupees becomes roughly 30.9 lakh rupees a year, or about 2.58 lakh a month. This number shocks most people, and that is precisely the point: it is the real target your savings must hit, not today’s comfortable 60,000.

Step 3: Decide how long the money must last

With life expectancy rising, planning for 25 to 30 years after retirement is prudent – if you retire at 60, assume the money must stretch to 85 or 90. This is the step people resist, because it makes the target bigger, but outliving your savings is the one retirement risk you cannot fix by working harder later. A conservative plan assumes you live longer than you expect.

Step 4: Convert annual need into a corpus

Now the key question: how large a lump sum, earning a realistic post-retirement return, can fund 30.9 lakh rupees a year for 30 years? Financial planners often use a shortcut – multiply the first year’s retirement expense by 25 to 30 – which here gives roughly 7.7 to 9.3 crore rupees. A more careful calculation treats it as the present value of a growing annuity: assuming your investments earn 8 per cent after retirement while expenses keep rising at 6 per cent, the corpus needed is the first year’s expense multiplied by a factor of about 22, which works out to roughly 6.8 crore rupees. The exact figure depends on your return and inflation assumptions, but the order of magnitude is what matters: for a 60,000-a-month lifestyle today, a 35-year-old needs something like 7 crore rupees at age 60. Online retirement calculators do this annuity maths for you – the important thing is to use realistic inputs, not optimistic ones.

Step 5: Work backwards to a monthly investment

The final step converts the distant target into today’s action. Ask: what monthly investment, growing at an assumed pre-retirement return, reaches the corpus in the years remaining? Assuming a 12 per cent annual return from equity-oriented investments over 25 years, reaching 7 crore rupees needs a monthly investment of roughly 28,000 to 30,000 rupees, stepped up each year as income grows. That is the power of starting early: the same corpus demanded of a 45-year-old with only 15 years left would need monthly investments more than three times as large. The maths rewards time far more than it rewards clever fund selection.

What the method leaves out – and what to add

This calculation covers living expenses. Layer on top: a separate emergency fund, health insurance adequate for private hospitals (medical inflation runs hotter than general inflation), and any big-ticket goals like a child’s wedding. Also revisit the maths every two to three years – salaries, expenses and assumptions drift, and a plan that is never updated is barely a plan. The method’s real value is not precision but direction: it replaces a vague hope of “saving enough” with a number, a monthly figure, and a yearly review.

FAQs

What inflation rate should I assume?

Most planners use 6 per cent for general expenses and 8 to 10 per cent for medical costs. Using a lower rate flatters the target but risks falling short.

Should I include my EPF and PPF in the corpus?

Yes – the corpus is the total needed, and existing EPF, PPF and NPS balances, projected to retirement at conservative growth rates, count toward it. The monthly investment you calculate is the gap after those.

What if I plan to retire early?

Early retirement squeezes from both ends: fewer years to save and more years to fund. Rework the calculation with the earlier retirement age – the required monthly investment rises steeply.

Source: Moneycontrol