Most SIP calculators ask you to picture the future: invest ₹5,000 a month for 20 years, get X lakhs. Useful, but hard to feel — it's a made-up future, and it doesn't cost anything to imagine a future that hasn't happened yet.
This calculator flips that around. Enter a date of birth, and it works out exactly how many days that person has lived — then shows what that many days of investing ₹1, ₹100, or ₹1,000 a day would be worth today, growing at 12% a year. It's the same compounding math behind any SIP calculator, just applied to a number that's already real instead of one that's still hypothetical.
The question it's built to answer
Not "what if you invest for 20 years," but "what if every day you've already lived had a rupee riding on it, compounding at 12%, starting the day you were born." That single reframe is what makes the number land differently — it isn't a projection you have to trust, it's built entirely from days that have already passed.
How it works
Enter a date of birth. The tool counts the exact number of days between then and today — no rounding.
It then runs that day-count through three lanes: ₹1 a day, ₹100 a day, ₹1,000 a day. For each one, it shows two figures side by side — the total amount invested, and what that amount would be worth today if it had compounded at 12% a year the entire time.
A worked example, at age 30
At age 30, a person has lived roughly 10,950 days. Here's what the ledger shows for that timeline:
| Daily amount | Total invested | Value today @ 12% |
|---|---|---|
| ₹1 / day | ₹10,950 | ~₹31,500 |
| ₹100 / day | ₹10.95 lakh | ~₹31.5 lakh |
| ₹1,000 / day | ₹1.1 crore | ~₹3.15 crore |
The invested column is just multiplication — anyone can do that in their head. The value-today column is compounding doing what compounding does when nobody interrupts it. That gap between the two columns is the whole argument for starting early, shown instead of stated.
Why the gap matters more than the total
Nobody can go back and start on day one — that's not really the point of the calculator. The point is what the gap between the two columns shows: a small daily amount, left alone to compound, does most of the work by itself over a long enough stretch.
And this is the part that's actually useful, not just a novelty: ₹100 a day starting today still has an entire remaining runway ahead of it. For anyone already running a SIP, this is a quick way to see the shape of consistent daily investing over decades, using their own timeline instead of a generic 20-year projection. For anyone not running one yet, it's a reason to start this week instead of next year.
Frequently asked questions
Does this store my date of birth anywhere?
No. Everything runs in your browser. Nothing is sent to or saved on any server.
Can I check amounts other than ₹1, ₹100, ₹1,000?
Those three are shown so you can compare small, medium, and serious daily amounts at a glance. The invested side scales exactly linearly — double the amount, double the number. The compounded side scales almost exactly the same way, so you can estimate anything in between in your head.
Is 12% a realistic number to use?
It's a commonly used long-term reference figure for Indian equity mutual funds over full market cycles — not a promise, and not any single year's return. Actual returns depend on the funds you pick and the years you hold them. Check a fund's real historical performance before investing based on any calculator, including this one.
See what your own days are worth.
Open the calculator →This is for illustration only and is not investment advice. Please consult a qualified financial advisor before making investment decisions. Returns shown are illustrative and not guaranteed; actual market returns vary and can be negative in any given year.