Buy now on EMI, or save via SIP and buy later?

There is no universal answer, it genuinely depends on the rates you enter. If your loan's interest rate is high relative to the return you'd realistically expect from saving, buying now on EMI can work out cheaper, because you avoid both the interest-on-interest of a long loan and you dodge future price inflation on the item. But if you can earn a SIP return meaningfully above both the loan rate and the item's price inflation, saving first can end up costing less in total cash outlay, at the cost of not having the item immediately. This tool runs the maths on your own entered assumptions rather than asserting one path is always right.

Yes. The price inflation input grows the item's price every year you spend saving instead of buying, so the SIP path has to reach a moving, rising target rather than today's price. That is what makes the comparison realistic, buying later is only actually cheaper if your savings growth outpaces both the loan rate you'd otherwise pay and this price inflation.

This version compares the two paths assuming you start from zero savings, a full loan on the EMI side and a SIP built up from scratch on the savings side. If you already have a lump sum saved, the fairest comparison is to first deduct it from the item's price before entering it here, on the EMI side that lowers your loan amount, on the SIP side you'd effectively need a smaller final corpus. Splitting a partial lump-sum plus ongoing SIP top-up scenario is a further extension we may add later, treat it as a current scope limitation of this tool.

To keep the comparison fair. If the EMI path let you pay less per month than the SIP path, or vice versa, you would not be comparing like with like, someone with less monthly capacity in one scenario would obviously come out worse. Using the EMI amount as the SIP contribution too means both paths draw exactly the same amount from your monthly budget, so the difference in total cost comes purely from interest rates, SIP returns and price inflation, not from unequal monthly effort.