SIP calculator with step-up, inflation and goal planning

Each instalment is invested at the start of its month and compounds monthly, so FV = P × ((1 + i)ⁿ − 1) ÷ i × (1 + i), where P is the monthly amount, i is the monthly rate (annual rate ÷ 12 ÷ 100) and n is the number of months. ₹5,000 a month at 12% for 10 years has i = 0.01 and n = 120, which gives about ₹11,61,695 from ₹6,00,000 invested.

It raises the monthly amount by a fixed percentage after every 12 months, the way a step-up SIP keeps pace with a rising salary. With a 10% step-up, ₹5,000 a month becomes ₹5,500 in the second year, ₹6,050 in the third and about ₹11,790 in the tenth. At 12% over 10 years that grows to about ₹16,87,163 from ₹9,56,245 invested, against ₹11,61,695 without the step-up.

Goal mode turns the maturity formula round: P = FV × i ÷ (((1 + i)ⁿ − 1) × (1 + i)). To reach ₹1 crore in 20 years at 12%, i = 0.01 and n = 240, so P is about ₹10,009 a month. The year-by-year table then shows how that SIP builds up to the target.

You choose, and the formula panel states which. Yearly, the default, uses FV = A × (1 + r)^years, the way fund returns (CAGR) are quoted: ₹1,00,000 at 12% for 10 years becomes ₹3,10,585. Monthly uses FV = A × (1 + r ÷ 12)^months and gives ₹3,30,039 for the same figures, because each month's growth starts earning growth of its own.

Enter an inflation rate and the maturity value is also shown divided by (1 + inflation)^years, which is what that sum would buy today. ₹11,61,695 after 10 years of 6% inflation is worth about ₹6,48,685 in today's money. The return you enter is an assumption, not a promise: market returns vary from year to year, and fund expenses, exit loads and tax are not included.