Work backwards from a target amount (a car, a down payment, a child's education) to find the monthly SIP needed to get there.
This calculator works backward from a target amount — a car, a wedding, a child's education fund — to figure out how much you need to invest monthly to reach it, given your time horizon and expected rate of return. It uses the standard SIP future-value formula in reverse, solving for the monthly instalment rather than the final corpus.
If you already have some savings earmarked for this goal, the calculator first grows that existing amount to your goal date, then works out the smaller monthly SIP needed to cover just the remaining gap.
For short time horizons, it's safer to assume a conservative return (closer to FD/debt-fund rates, 6-8%) rather than equity-level returns, since equity markets can be volatile in the short term and you may not have time to recover from a downturn.
Many investors use a 'step-up SIP' — increasing the monthly amount each year in line with rising income — to reach goals faster or with less strain early on. This calculator assumes a flat monthly amount for simplicity.
Revisit the numbers periodically — if you've under-invested for a period, either the monthly amount needs to increase for the remaining time, or the goal timeline needs to extend.