A monthly investment of ₹5,000 in mutual fund SIPs will take 1.6 years, or over 18 months, at an expected return rate of 12% to achieve a corpus of a little over ₹1 lakh. However, increasing the monthly investment by ₹500, i.e. an SIP of ₹5,500, will yield a corpus of ₹1 lakh in 18 months at same return rate.