Comparing
1) http://www.investmentyogi.com/sip-return-calculator.aspx and
2) http://www.indiainfoline.com/Personalfinance/calculators/MutualFunds/Systematic-Investment-Plan-Returns.aspx
With the same inputs: 40,000 monthly, 18 years or 216 months and 15% CAGR, each of them are giving different outputs. What can be a possible explanation behind this? The first one returns 388.4 lakhs and the second one returns 441 lakhs! Not even close. Is the first one after tax deductions?
How are tax deductions calculated on SIP?