Compounding
What a five-year delay actually costs
Everyone accepts in principle that starting early helps. Very few have looked at the size of the number. It is larger than intuition suggests, and the reason why is worth understanding.
Take two investors. Both invest ₹10,000 a month. Both stop at age 60. One starts at 25, the other at 30. Everything else is identical, including the assumed 12% per annum return.
| Starts at | Years invested | Total invested | Illustrative value at 60 |
|---|---|---|---|
| Age 25 | 35 | ₹42.0 lakh | ₹6.43 crore |
| Age 30 | 30 | ₹36.0 lakh | ₹3.53 crore |
The five-year delay cost ₹2.9 crore. The additional amount invested by the earlier starter was ₹6 lakh. Six lakh of instalments produced a difference of nearly three crore.
Why the number is so large
Because compounding is back-loaded. In the final year of a 35-year plan, the corpus grows by roughly its own annual return on a very large base — an amount far greater than any single year’s instalments. The investor who starts five years earlier does not gain five years of contributions; they gain five years at the far end, where the growth per year is biggest.
Put differently: the instalments you skip at the start are small, but the years you lose at the end are the largest ones. That asymmetry is the whole story.
The mirror image
This is also why stopping a SIP early is so costly. Pausing for two years in your thirties removes two of the smallest instalment years — and two of the largest compounding years.
Catching up
If you have lost five years of a twenty-year goal, the required monthly amount rises sharply.
| Situation | Monthly required for ₹1 crore |
|---|---|
| 20 years remaining | ₹10,010 |
| 15 years remaining | ₹20,020 |
| 10 years remaining | ₹43,470 |
At an assumed 12% per annum. Losing five years roughly doubles the monthly requirement; losing ten more than quadruples it. The money has to come from somewhere, which usually means a materially lower standard of living in the intervening years.
If the time is already gone
The arithmetic cuts both ways, and this is the part worth holding on to. If you are 42 and have not started, the eighteen years ahead of you are still the most valuable eighteen years available to you. They will never be worth more than they are today. The mistake is not the late start — it is treating a late start as a reason to delay further.
- Start at a sustainable amount. Not the ideal amount. The one you will still be paying in three years.
- Add a step-up. A 10% annual increase closes a surprising amount of the gap over fifteen years. See how a rising SIP compares.
- Direct windfalls to the goal. Bonuses and maturities added as lumpsums do disproportionate work when the horizon is short.
- Revisit the target, honestly. If the number is unreachable, a later retirement date or a smaller target is a real answer. A higher assumed return is not.
The one thing not to do
Do not wait for a better entry level. The investor who waits for a correction is making the same mistake as the one who delayed for five years, only with a shorter name for it. Time in the market is the variable you cannot buy back later.
Enter your own age and amount in the delay cost calculator to see what a specific delay costs in your case. The projection assumes a constant rate of return; real markets do not provide one, and mutual fund investments are subject to market risks.
Common questions
Why does a small delay cost so much?
Because the final years of a long investment carry the largest absolute growth. A corpus grows on its whole accumulated value, so the years you lose are the biggest ones, even though the instalments you skipped were the smallest.
I have already lost ten years. Is there any point?
Yes. The same arithmetic says the next ten years are the most valuable ones you still have. Delaying further compounds the original problem; it does not undo it.
Can a larger instalment make up for a late start?
Partly. Catching up on a five-year delay in a twenty-year goal typically needs roughly 45 to 55% more per month. It is possible, but it costs considerably more of your income than starting on time would have.
Is it better to wait until I can invest a meaningful amount?
No. ₹2,000 invested now generally beats ₹10,000 invested in five years, for the same reason a delay is expensive. Start at whatever amount is sustainable and use a step-up to raise it.
Does this argument hold if markets fall?
The arithmetic assumes a constant rate, which markets do not provide. Over long horizons, more time invested has historically been an advantage, but it is not a guarantee, and a poor final decade would change the outcome.
What about waiting for a market correction?
Time out of the market usually costs more than the entry price saved. Investors who wait for a better level often stay out through the recovery as well.
Work through your own numbers