SIP Calculator
A SIP Calculator is a simple online tool that estimates how much wealth your monthly SIP can build over a target horizon, given an assumed annual return. Most Indian brokers, AMCs and personal-finance websites offer free SIP calculators. Used wisely, they help you plan goals — retirement, child’s education, home down payment — and decide how much to invest each month.
Key takeaways:
- SIP calculators estimate future value of a monthly investment given assumed returns.
- Inputs: monthly SIP amount, period (years), expected annual return.
- Outputs: total invested, expected returns, expected final corpus.
- Compounding is the magic ingredient — small differences in tenure or return have huge impact.
- Use realistic return assumptions (10–12% for equity SIPs in long term).
How a SIP calculator works
It uses the standard formula for future value of an annuity:
FV = P × [((1 + r)^n − 1) / r] × (1 + r), where P = monthly SIP, r = monthly return (annual return / 12), and n = number of months. The result is the corpus at the end of the SIP period assuming a steady return.
Worked example
| SIP / month | Years | Return % | Estimated corpus |
|---|---|---|---|
| ₹5,000 | 10 | 12% | ~₹11.6 lakh |
| ₹5,000 | 20 | 12% | ~₹50 lakh |
| ₹10,000 | 20 | 12% | ~₹1 crore |
| ₹15,000 | 25 | 12% | ~₹2.8 crore |
Why compounding compounds
Most of the corpus in a long-term SIP is gains, not principal. A 20-year SIP can have gains 3–4× the invested amount. Time is the most underrated input in any SIP calculation — doubling the tenure can quadruple the final corpus.
Common mistakes when using SIP calculators
- Using over-optimistic return assumptions (15–20% sustained returns are unrealistic).
- Ignoring inflation — a ₹1 crore corpus in 20 years is worth less in today’s rupees.
- Forgetting that SIPs can be increased over time.
- Treating estimates as guarantees — actual returns vary year to year.
How to plan with a SIP calculator
- Define your goal in today’s rupees (e.g., ₹1 crore retirement).
- Adjust for inflation to get the future value of that goal.
- Use the calculator to find the monthly SIP needed.
- Build in a step-up — increase SIP each year as income grows.
- Re-evaluate periodically and adjust based on actual returns.
Beyond plain SIP calculators
Advanced calculators allow step-up SIPs (annual percentage increase), goal-based planning, and what-if scenarios. Lemonn’s SIP and goal calculators are useful for visualising long-term plans. Many investors also use Monte Carlo simulators to see how variable returns affect corpus.
Frequently asked questions
What return should I assume in a SIP calculator?
For equity funds, 10–12% CAGR is a reasonable long-term assumption. Debt fund SIPs are typically 6–8%.
Should I include inflation?
Yes. Calculate the goal in future value or discount the corpus to today’s rupees.
Is the calculator’s output guaranteed?
No. It is an estimate based on assumed returns; actual results will vary.
Does Lemonn have a SIP calculator?
Yes — Lemonn offers SIP and goal calculators alongside fund discovery and tracking.
