The retirement planner asks for more inputs than any other calculator on this website, and its answer is the one people find hardest to believe. Both follow from the nature of the goal: it is far away, it lasts a long time, and prices rise throughout. This guide walks through the retirement planner as it works on 11 October 2026.
Key points
- The planner estimates what your current expenses would be at retirement, the corpus that could support them, and a monthly SIP towards that corpus.
- Four of the eight inputs are assumptions about the future. Small changes in them move the answer a great deal.
- Every result is an illustration, not a forecast and not a recommendation.
- The useful output is not one number but the range you get from trying several assumptions.
- It leaves out tax, pensions and other income, and uneven market returns.
The eight inputs
| Input | What to enter | Range |
|---|---|---|
| Current age | Your age today | 18 to 70 |
| Retirement age | When you expect to stop earning | 40 to 80 |
| Current monthly expenses | What the household spends now, at today’s prices | ₹5,000 to ₹10,00,000 |
| Assumed inflation | The yearly rise in your expenses | 0% to 12% |
| Assumed return before retirement (%) | A constant yearly rate on investments until retirement | 0% to 20% |
| Assumed return after retirement (%) | A constant yearly rate on the corpus during retirement | 0% to 15% |
| Years in retirement | How long the corpus must last | 1 to 40 |
| Existing savings for retirement | What you have already set aside, if anything | Optional, up to ₹10 crore |
Notes on the inputs that cause most trouble:
- Expenses, not income. Enter what you spend. Leave out costs that will end before retirement, such as a home loan instalment or school fees, and add ones that will grow, such as healthcare.
- Years in retirement. Plan for a long life. Running out of money at 85 is a worse problem than leaving some unspent.
- Return after retirement. This is usually set lower than the return before retirement, because money being drawn on is generally kept in steadier assets.
- Existing savings. Include only money you will not use for anything else.
The planner opens with example values filled in. They are placeholders so that an example can be shown, not forecasts or indications of likely returns. Replace all of them.
What the planner works out
- Monthly expenses at retirement. Current expenses × (1 + inflation) raised to the number of years left.
- Corpus needed at retirement. The amount that could fund one withdrawal at the start of each retirement year, starting at twelve times that monthly expense and rising with inflation every year, with the remaining balance assumed to earn the after-retirement return.
- Future value of existing savings. Your existing savings grown at the before-retirement return.
- The gap. Corpus needed less the future value of existing savings.
- Monthly SIP to cover the gap. The level monthly amount that would reach the gap at the before-retirement return. If there is no gap, the SIP shown is zero.
The tiles and chart show the years up to retirement only.
A worked illustration
A hypothetical case using round numbers, which are also the values the planner opens with: age 30, retiring at 60, current expenses ₹50,000 a month, inflation assumed at 6%, returns assumed at 8% before and 7% after retirement, 25 years in retirement, no existing savings. These rates are assumptions for arithmetic. They are not forecasts, and no investment earns the same rate every year.
| Result | Illustrative figure |
|---|---|
| Monthly expenses at retirement, in future rupees | About ₹2.87 lakh |
| Corpus needed at retirement | About ₹7.71 crore |
| Monthly SIP to cover the gap | About ₹51,400 |
The corpus looks enormous because it is expressed in the rupees of thirty years from now, when ₹2.87 lakh a month buys what ₹50,000 buys today.
How much each assumption matters
Change one input at a time and keep the rest as above.
| Change | Corpus needed | Monthly SIP |
|---|---|---|
| Base case | ₹7.71 crore | ₹51,400 |
| Inflation 7% instead of 6% | ₹11.42 crore | ₹76,100 |
| Return before retirement 6% instead of 8% | ₹7.71 crore | ₹76,400 |
| Starting at age 40 instead of 30 | ₹4.31 crore | ₹72,700 |
| Existing savings of ₹10 lakh | ₹7.71 crore | ₹44,700 |
All figures are illustrative and rounded.
What the table shows:
- One percentage point of inflation raises the required SIP by about half. Inflation acts twice, before retirement and during it.
- Two percentage points less return has a similar effect. Assuming a high return to make the SIP look affordable is the easiest mistake to make with this tool.
- Starting ten years later needs a much larger monthly amount even though the corpus is smaller in rupee terms, because there are ten fewer years of contributions and growth.
- Money already set aside has thirty years to grow in this example, so a modest sum reduces the SIP noticeably.
This is why a single answer from the planner should not be trusted. A range, built from cautious and less cautious assumptions, is more honest and more useful.
A sensible way to use it
- Enter your real age, expenses and savings.
- Run a cautious case: higher inflation, lower returns, a long retirement.
- Run a moderate case.
- Note the SIP in each. The gap between them is the uncertainty you are planning under.
- Compare with what you can invest now. If it is less, see what a yearly increase in your SIP would do, using the step-up calculator. Step-up SIP explained describes the facility.
- Come back once a year and update the inputs.
If the figure is out of reach, the levers are: start now with what you can, raise contributions as income grows, retire later, or plan for lower expenses. Assuming a higher return is not a lever. It is only a different guess.
What the planner leaves out
- Uneven returns. Markets do not deliver a constant rate. Poor returns early in retirement, while withdrawals are being made, do more harm than the same returns later. The planner cannot show this.
- Tax. Withdrawals may be taxable, which means the corpus has to be larger than the planner suggests. Tax rules change, so confirm the position with a tax professional.
- Other income. Pension, provident fund, rent or an annuity reduce what the corpus must provide. You can allow for them by entering lower expenses or by including the lump sums in existing savings.
- Large one-off costs such as medical treatment, a child’s wedding or home repairs.
- Changing spending. Expenses in retirement rarely rise in a straight line.
- Scheme costs and exit loads.
From a number to a plan
The planner gives a target and a monthly amount. It does not say how the money should be invested. That depends on how many years remain and how much volatility you can live with, and the mix normally becomes steadier as retirement approaches. Our retirement planning page covers accumulation, withdrawal through an SWP and how the mix usually changes with age. If retirement is competing with other goals, see deciding what comes first.
If you would like to go through your own figures with us, you can contact us. Any inputs we provide are incidental to mutual fund distribution and are illustrations, not a paid financial plan.
Risk note
All results are illustrative and depend on the assumptions entered. Mutual fund returns are not guaranteed, and a corpus can fall in value before or during retirement.
Frequently asked questions
Why is the corpus figure so large?
Because it is in future rupees. Thirty years of inflation at 6% multiplies prices nearly six times.
What inflation rate should I assume?
Nobody knows the future rate. Try more than one figure, and remember that household costs such as healthcare can rise faster than the general average.
Does the planner tell me what my investments will be worth?
No. It shows what a given SIP would amount to if the assumed rate were earned every year, which will not happen exactly.
I already have provident fund and other savings. Where do they go?
Enter the amount earmarked for retirement under existing savings. The planner grows it at the assumed before-retirement rate.