Your SIP's big number, in today's rupees.

Two questions, one page. What does my SIP grow to, in today's rupees? And what SIP does my goal need? The maths runs on this page and nothing is sent anywhere.

Our calculation. You invest at the start of each month; the yearly return is spread evenly over 12 months; the SIP rises once a year. Today's rupees divide by inflation compounded over the same years. Savings you already have grow at the same return. Before tax and exit loads. The return is your assumption, not a forecast.

Every SIP calculator ends on one big number. ₹1.86 crore in 20 years sounds like freedom. But a crore in 2046 won't buy what a crore buys today.

So we divide by inflation. At 5% a year for 20 years, prices go up about 2.65 times. That ₹1.86 crore buys what about ₹70 lakh buys now. Still a lot of money. Just not the number on the screen.

The step-up gets the same treatment. Raising ₹10,000 by 10% a year means ₹61,159 a month in year 20. In today's rupees that's about ₹24,200, so your real SIP grew about 2.4 times, not 6. The step-up is what keeps a ₹10,000 SIP from shrinking in real terms while your salary grows.

The step-up costs you ₹44.7 lakh more over 20 years and adds about ₹35.6 lakh in today's rupees. And a goal of ₹50 lakh in today's money, 15 years away, at 11% and 6% inflation, needs a SIP of about ₹15,531 a month to start, rising 10% a year.

Illustrative, our calculation. Returns are assumptions, not forecasts. No fund named.

Claude is good at turning "my child's college" into a clear question and saying its assumptions out loud. It's not where you trust the arithmetic. So: three prompts in your own Claude account, then type Claude's numbers into What SIP my goal needs above and check they match. If they don't, the calculator wins. Nothing you type comes to us.

Prompt 1: turn the goal into numbers

I'm planning for my child's higher education. Don't recommend any fund,
scheme, bank or product, and don't tell me what to buy. Help me with the
numbers only. Ask me, one question at a time: my child's age now, the age
they'll start college, what that course would cost if we paid for it today
(in rupees), and how much I've already saved for it. Then put my answers
in a short table.

Prompt 2: the assumptions, out loud

Now list the assumptions this plan needs: general inflation, education
inflation, and the yearly return I assume after costs. For each one, show
me a cautious value and a hopeful value and why, and tell me which official
source I could check (for example RBI for the inflation target, MoSPI for
CPI). Don't pick for me. I'll choose the values.

Prompt 3: the arithmetic, shown

Using my answers and the values I choose below, work out:
1) the course cost in the year my child starts, in that year's rupees;
2) the monthly SIP that reaches it, flat, and with a 10% yearly step-up.
Show every formula and every step so I can check it in a spreadsheet.
Values I choose: inflation [x]%, education inflation [y]%, return [z]%.

Works in any capable AI assistant; we show it in Claude. The prompts tell it not to name any fund or product. If it does anyway, ignore that part: that's a pick, and picks aren't what this is for. Education inflation has no single official figure, so it's your assumption. Prompt pack v1.0, 22 October 2026, CC BY 4.0.

This tool runs on your assumptions, not on tax law. The one outside number on the page is the inflation target we mention, from this official source.

• Real returns go up and down. This uses one steady return, so the real path will look bumpier and can end lower or higher.
• Before tax and exit loads. Gains on equity funds are taxed when you sell.
• Your goal's own costs can rise faster or slower than the inflation you type in. Use the rate that fits the goal.
• An AI can get compound arithmetic wrong, even when its formula looks right. That's why the prompts end in this calculator.
• Some calculators divide the yearly return by 12. We use the monthly rate that compounds to exactly your yearly return, so our numbers can be slightly lower.

Tested against 12 cases checked with a separate closed-form calculation (v1.0, 21 October 2026), matched to the rupee. v1.1 (29 October 2026) adds "already saved" to the goal planner, with 6 more cases.