The Problem With "Just Start a ₹5,000 SIP"
Most people start a SIP with a round number — ₹5,000, ₹10,000, ₹25,000 — because it "feels right" or because that's what they can afford. This is better than not investing at all, but it's like driving without knowing your destination.
The right approach: start with the goal, then calculate backward.
The Reverse SIP Formula
For any financial goal, you need three numbers:
- Target amount (how much you need, adjusted for inflation)
- Time horizon (how many years until you need the money)
- Expected return (based on your fund category)
The formula:
Monthly SIP = Target Amount × [r / ((1+r)^n - 1)]
Where r = monthly return rate (annual return / 12) and n = total months.
Real Examples
| Goal | Amount Needed (Today) | Inflated Amount (6%) | Years | Expected Return | Monthly SIP |
|---|---|---|---|---|---|
| Child's Education | ₹25 lakh | ₹45 lakh (10y) | 10 | 12% | ₹19,500 |
| House Down Payment | ₹20 lakh | ₹27 lakh (5y) | 5 | 10% | ₹35,000 |
| Retirement Corpus | ₹3 Cr | ₹5.4 Cr (25y) | 25 | 12% | ₹28,500 |
| World Tour | ₹5 lakh | ₹6.7 lakh (5y) | 5 | 10% | ₹8,700 |
| Car Purchase | ₹10 lakh | ₹11.9 lakh (3y) | 3 | 8% | ₹30,000 |
Notice how the required SIP varies dramatically based on time horizon. The retirement goal needs ₹5.4 Cr but only ₹28,500/month because you have 25 years of compounding. The car needs only ₹11.9 lakh but requires ₹30,000/month because 3 years isn't enough for compounding to work.
The Inflation Adjustment Most People Skip
If your child's education costs ₹25 lakh today but they'll go to college in 10 years, you don't need ₹25 lakh — you need ₹45 lakh (at 6% education inflation). Planning with today's costs is the #1 reason people fall short of their goals.
Always inflate your goal amount before calculating the SIP.
What Return Should You Assume?
Be realistic, not optimistic:
| Fund Category | Conservative Estimate | Don't Assume More Than |
|---|---|---|
| Large Cap / Index | 10-11% | 12% |
| Flexi Cap | 11-12% | 13% |
| Mid Cap | 13-14% | 15% |
| Small Cap | 14-15% | 16% |
| Debt Fund | 6-7% | 8% |
Using inflated return expectations means you'll save less than needed. It's better to over-save slightly and have a surplus than to under-save and scramble at the end.
One SIP Per Goal — The Mapping Principle
Don't run one ₹30,000 SIP and mentally assign it to "everything." Instead:
- ₹19,500 in Fund A → mapped to "Child Education"
- ₹8,700 in Fund B → mapped to "World Tour"
- ₹28,500 in Fund C → mapped to "Retirement"
Why? Because each goal has a different time horizon, which means a different fund category. Your retirement SIP (25 years) can be in a mid cap or small cap fund. Your car SIP (3 years) should be in a debt or balanced advantage fund. Mixing them in one fund means the wrong risk level for at least one goal.
When ₹5,000/Month Is All You Have
If you can only afford ₹5,000/month, don't feel discouraged. Here's what to do:
- Prioritise one goal: Start with the most important one (usually emergency fund → retirement → other goals)
- Use step-up SIP: Increase your SIP by ₹500-1,000 every year as your income grows
- ₹5,000/month at 12% for 25 years = ₹95 lakh — that's nearly ₹1 Cr from just ₹5,000/month
How Our Planner Does This Automatically
In FinPlann, you add goals with target amounts and timelines. The planner automatically inflation-adjusts, calculates the required SIP per goal, compares it with your existing SIPs, and shows the gap. The Goal-wise Investment Plan then suggests specific fund categories and monthly amounts — so you know exactly what to invest, where, and how much.