What this retirement calculator answers
It tells you the chance that your retirement money lasts as long as you do. Most retirement calculators grow your savings at one fixed return and hand you a single number. This one runs your plan through 1,000 different futures, each built from real month-by-month swings of Indian mutual fund categories, and counts how many of them leave money in the account at the age you choose. The answer is a probability, a bad case and a range, which is closer to how retirement actually goes.
Why one number is not enough
A fixed-return calculator quietly assumes that markets go up by the same amount every year. They do not, and in retirement the order of good and bad years matters as much as the average. A crash in the first years after you stop working forces you to sell while prices are down, and that money never gets the recovery. The same crash fifteen years later does far less damage.
Here is that effect with real history. Both lines below earn exactly the same average return, because they are built from the same months of the Flexi Cap category average. One retiree lives those months in the order they happened. The other lives them in reverse.
Same returns, different order
₹1.00 Cr at retirement, ₹70k a month withdrawn and raised 6% a year, invested in the Flexi Cap category average. Both retirees earn the same 11.2% a year on average. One ends with ₹1.02 Cr; the other ends with ₹42 L.
Same months, same average, a very different retirement. A single-number calculator cannot show you this. A probability can.
How the 1,000 futures are built
- Your plan, month by month. While you work, the calculator adds your monthly investment, raised by the yearly increase you set. From the month you retire, it withdraws what your household spends, raised with inflation every year.
- Real swings, re-centred. Each future strings together 12-month stretches drawn at random from the Flexi Cap category average while you save, and the Conservative Hybrid category average after you retire, using months from February 2013 onward. The record is treated as a loop, so the first and last months are drawn as often as the rest. Each series is then shifted so its compound yearly average (its CAGR, the way fund returns are quoted) matches the return you chose. The size, frequency and order of the swings come from history; the average is your assumption.
- Count the survivors. A future fails in the month the money runs out. The headline is the share of the 1,000 futures that reach your chosen age with money left.
The same inputs always give the same answer: the futures are fixed, so moving a slider changes only your plan, never the dice.
How to read the result
- The percentage is the share of futures in which the money lasted. There is no single right target, but the lower it is, the more of your retirement you are leaving to luck.
- The bad case is the 1-in-10 future: the age at which it runs dry, or that it still lasts.
- The band on the chart holds 8 in 10 futures; the line is the middle one. Everything on the chart is in today's rupees, so a corpus at 60 compares directly with what things cost now.
- The monthly investment for a 9-in-10 chance is what it would take to get there with everything else unchanged.
What it leaves out
The calculator is deliberately simple. It treats all your retirement money as one portfolio, ignores tax, assumes one level of spending that rises with inflation, and does not model pensions, rent or health shocks. It is a way to see how much risk sits inside a plan, not a forecast and not advice. The nyvo app works out the probability for your actual goals and holdings.