The 12% SIP Assumption: How to Build a Goal Plan That Still Works at 8%
Almost every SIP calculator in India starts with 12% as the default return. It is a reasonable number to try. It has also become the only number many people try, and that is where plans get fragile.
This article gives you a simple method, the Goal Stress Ladder, to test a goal at three different returns before you commit to a SIP amount. We run it on three goals that matter to salaried professionals in Bengaluru: a home down payment, a child’s education and retirement.
Where the 12% comes from
The figure has a basis. Historically, the Nifty 50 has often delivered about 12% over long windows. Outlook Money reports that about two out of three five-year periods for the Nifty 50 TRI ended above 12% a year, and that the index has delivered more than 10% over seven-year periods nearly 84% of the time (article). Capitalmind’s long-term study of 15-year SIPs found a wide range of outcomes around a central figure near 12% (The 12% Myth).
So 12% is a fair central estimate for a diversified equity portfolio held for a long time. But “two out of three” also means one in three did worse, and a calculator treats the future as if it were certain. Your goal plan has to survive the third that did worse.
The Goal Stress Ladder
The method has four steps.
- Inflate the goal. Take the cost in today’s money and grow it by an inflation rate for the number of years you have.
- Calculate the SIP at three rungs. Work out the monthly SIP needed at 8%, 10% and 12%.
- Find your rung. Choose the highest rung where the SIP fits your budget, then check what the lowest rung would ask of you.
- Decide your gap plan. If the 8% SIP is out of reach, decide in advance what you would adjust: the amount, the date or the target.
If the goal only works on the 12% rung, you have a plan that depends on good luck.
Three goals, three ladders
These are illustrations with assumed numbers. They use a fixed return per rung for the arithmetic, invest at the start of each month and ignore tax and fund costs. Real returns will not arrive in a straight line, a point we explored in our pillar article.
| Goal | Today’s cost | Inflation assumed | Years | Cost at that time |
|---|---|---|---|---|
| Home down payment | ₹30 lakh | 6% | 7 | ₹45.1 lakh |
| Child’s education | ₹25 lakh | 8% | 15 | ₹79.3 lakh |
| Retirement corpus | ₹3 crore | 6% | 25 | ₹12.9 crore |
Now the monthly SIP needed on each rung:
| Goal | At 8% | At 10% | At 12% | Extra needed at 8% vs 12% |
|---|---|---|---|---|
| Home down payment (7 yrs) | ₹40,399 | ₹37,615 | ₹35,022 | about 15% more |
| Child’s education (15 yrs) | ₹23,340 | ₹19,746 | ₹16,663 | about 40% more |
| Retirement (25 yrs) | ₹1,40,742 | ₹1,03,572 | ₹75,641 | about 86% more |
The pattern is clear. The longer your horizon, the more your plan depends on the return you assume. A 4-point difference in return changes a 7-year SIP by roughly a seventh. It changes a 25-year SIP by almost double. That is the power of compounding working in both directions.
Illustration with assumed inflation and returns. Not a forecast.
What the ladder does not show
The table does not predict that you will earn 8%, 10% or 12%. It shows the price of being wrong. A planner who assumes 12% and earns 8% on a 25-year goal ends up with about 46% less than the target if the SIP stays the same, since the required SIP at 12% (₹75,641) would grow to roughly ₹6.9 crore at 8%, against a target of ₹12.9 crore.
That is a calculation, not a warning to avoid equity. Equity has historically been the main way to grow money ahead of inflation over long periods. The warning is about planning on one number.
Real return matters more than the headline
Take the retirement row. A 12% nominal return and 6% inflation leave about 6% in purchasing power. If you plan only on the nominal figure and do not inflate the goal, you will think you have more than you do. That is why step 1 of the ladder comes first. Value Research makes the same point about real returns in SIP planning.
Match the return to the portfolio you own
A return assumption only makes sense for a specific mix of investments. A portfolio of conservative hybrid funds will not behave like a portfolio of equity index funds. If your SIP is split between debt, hybrid and equity, a single 12% figure is wrong for the debt part from the start. When you run the ladder, use a lower rung for the conservative part and a higher rung for the growth part, and add them. If you are unsure how your funds divide, our factsheet guide shows where to look.
Levers when the 8% rung is out of reach
Suppose the 8% SIP for your goal is more than you can afford today. You have four levers, and none of them requires a better fund.
Raise the SIP every year. This is the strongest lever for salaried people, whose pay rises over time. Take a ₹15,000 monthly SIP for 15 years at 10%. Held flat, it grows to about ₹60.2 lakh. If you raise it by 5% each year, it grows to about ₹79.6 lakh, which is close to the ₹79.3 lakh education target in our example, and the total invested rises from ₹27 lakh to ₹38.8 lakh. (Assumed returns, illustration only.)
Move the date. One more year of investing often closes a larger gap than a small rise in return.
Lower the target. A smaller down payment or a state-college plan changes the arithmetic. This is a decision for you and your family.
Split the goal. Part of the goal might be funded by existing savings, a provident fund or a gift.
A scenario: variable pay and a fixed SIP
Nikhil, 33, works at a product company in Bengaluru, and about 20% of his pay is variable. He set a SIP equal to what he can afford in a month when his bonus is delayed. We made up Nikhil. If he runs the ladder on his down payment goal and finds that the 8% rung is affordable only with his full variable pay, he has two options: set the SIP at the floor he can always meet and add lump sums when bonuses arrive, or accept a later date. Either way, he knows the cost of a weaker market before it arrives.
At Artha Vridhi, our SIP planning process begins with this ladder: a goal, a date and three return rungs, before any fund is named.
When this method does not fit
The ladder assumes you can wait. If your goal is less than three years away, equity returns are too uncertain to plan around, and the right tool is a conversation about lower-risk options and the date itself. It also assumes you will keep investing. A plan that breaks the first time you lose a job needs an emergency fund first.
Frequently asked questions
Is 12% a realistic SIP return?
It is a reasonable long-term estimate for a diversified equity portfolio, and a poor estimate for any single year. Many years fall below it. Plan on a range.
What return should I use for a goal 5 years away?
Use a lower assumption than for a 20-year goal, and consider a lower-risk mix. A short horizon leaves little time to recover from a down year.
Should I use 8% for everything?
No. Use 8% as a stress case, not as a forecast. The point is to see whether your plan survives it.
How do I account for inflation?
Grow your goal’s cost by an inflation rate before calculating the SIP. Education costs have often risen faster than general prices, so some families use a higher rate for that goal.
Can you run the ladder for my goals?
Send us your goal, date and current SIP on WhatsApp and we will do it with you.
Disclosures
Mutual fund investments are subject to market risks, read all scheme-related documents carefully.
Artha Vridhi is an AMFI-registered Mutual Fund Distributor (ARN-362803). This article is for education and is not personal investment advice. All figures are illustrations based on assumed inflation and returns, and they are not forecasts or promises of return. Distributors are paid commission by fund houses on regular-plan investments.