Waiting Five Years to Start Investing Costs More Than You Think. Here's the Compounding Math
6 min read
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6 min read
Two friends both decide to invest Rp1.000.000 every month. One starts at 25. The other says, "I'll start at 30, after I settle in."
Both stop at 55. Both earn the same return. The late starter put in only Rp60.000.000 less. So how big is the gap at the end?
It is about Rp539.000.000. This post shows where that number comes from. It is the cost of delaying investing 5 years, and it is much larger than the five years of savings you skipped.
Every figure below is a calculation with stated assumptions, not a forecast and not a promise of returns.
Here are the rules we use. We made them up to keep the math clean.
Nothing else differs. Same amount, same rate, same stop date. Only the start date changes.
| Friend A (starts at 25) | Friend B (starts at 30) | |
|---|---|---|
| Months of investing | 360 | 300 |
| Total money put in | Rp360.000.000 | Rp300.000.000 |
| Balance at 55 | Rp1.490.359.449 | Rp951.026.395 |
| Growth earned | Rp1.130.359.449 | Rp651.026.395 |
Friend A put in 20% more money (Rp60.000.000 on top of Rp300.000.000). But Friend A ends with about 57% more.
Why the mismatch? Because those first five years of deposits do not just sit there. They keep earning for the next 25 years. Money that goes in early gets the longest time to grow.
The balance comes from the future value of a regular monthly deposit.
Balance = P × ((1 + i)^n − 1) ÷ i
In plain words:
Compounding means your gains earn gains of their own. Last month's growth becomes part of the base that grows this month.
You can check Friend A. With n = 360, the formula gives Rp1.490.359.449. With n = 300 for Friend B, it gives Rp951.026.395.
If you want a quick feel for how fast money doubles, see the rule of 72 and doubling time.
Let's keep Friend A's plan as the baseline (start at 25, Rp1.000.000 a month, stop at 55). Now see what happens when you wait one, three, five or ten years. We keep the stop age fixed at 55.
| Years you wait | Months invested | Balance at 55 | Share of the no-delay balance |
|---|---|---|---|
| 0 | 360 | Rp1.490.359.449 | 100% |
| 1 | 348 | Rp1.364.644.687 | 91,6% |
| 3 | 324 | Rp1.141.380.571 | 76,6% |
| 5 | 300 | Rp951.026.395 | 63,8% |
| 10 | 240 | Rp589.020.416 | 39,5% |
Notice the shape. The first year of waiting costs you about 8% of the final balance. Waiting five years costs about 36%. Waiting ten years costs about 60%.
The cost gets heavier because the years you skip are the ones with the most time left to compound.
Say Friend B wakes up at 30 and wants to reach the same Rp1.490.359.449 by 55. How much must they invest each month?
Catch-up deposit = Rp1.000.000 × (1.490.359.449 ÷ 951.026.395)
The answer is about Rp1.567.106 a month. That is roughly 57% more every single month, for 25 years.
Here is the same catch-up for other delays, at the same 8% rate:
| Years you wait | Monthly deposit needed to match the no-delay balance |
|---|---|
| 1 | Rp1.092.123 |
| 3 | Rp1.305.752 |
| 5 | Rp1.567.106 |
| 10 | Rp2.530.234 |
Waiting ten years means you need more than two and a half times the monthly amount. For many people that is not a realistic jump.
The 8% rate is only an assumption. Here is the same five-year gap at other rates. The same Rp1.000.000 monthly deposit, 360 months versus 300 months.
| Annual return (assumed) | Friend A at 55 | Friend B at 55 | Extra monthly deposit B needs |
|---|---|---|---|
| 6% | Rp1.004.515.042 | Rp692.993.962 | Rp1.449.529 (+45%) |
| 8% | Rp1.490.359.449 | Rp951.026.395 | Rp1.567.106 (+57%) |
| 10% | Rp2.260.487.925 | Rp1.326.833.403 | Rp1.703.671 (+70%) |
Two things stand out. First, even at a modest 6%, the delay still costs a lot. Second, the higher the return, the bigger the price of waiting. That is how compounding works: a higher rate rewards time more.
At a return of 0%, delay would cost only the five years of deposits you skipped (Rp60.000.000). So the extra damage in the table above comes entirely from lost compounding.
A clean example hides real life. Please keep these in mind.
If you have no clear first step yet, read what to do with your first Rp10 million.
You do not need a perfect plan to begin. You need to see where you stand today.
Open your NetWort dashboard and add the assets you already hold. It shows your portfolio's total value and how it has grown over time. That gives you a real starting number to work from, and a way to check later whether your monthly habit is doing its job.