Index Fund Compare Calculator

What is the Index Fund Compare Calculator?

Index funds tracking the same index hold the same shares, so the main difference between them is cost. A seemingly small gap in expense ratio compounds into a large difference over 15–20 years. This index fund comparison calculator puts a rupee figure on it.

Enter a lump sum and/or monthly SIP, the holding period, the index's expected return and each fund's expense ratio plus tracking difference. The calculator shows both final values and how much extra wealth the cheaper fund produces.

How to use the Index Fund Compare Calculator

1. Lump Sum Invested (₹) (sample: 10,00,000)
2. Monthly SIP (₹) (sample: 0)
3. Holding Period (years) (sample: 15)
4. Index Return (% per year) (sample: 12)
5. Fund A Expense Ratio + Tracking Difference (%) (sample: 0.2)
6. Fund B Expense Ratio + Tracking Difference (%) (sample: 1)
7. Press Compare Funds (results also refresh as you type). The result card shows the Extra Wealth with the Cheaper Fund, along with Fund A final value, Fund B final value, Cheaper fund and Share of final value lost to the higher cost.

Formula used

Net return = Index return − (Expense ratio + Tracking difference)

• Lump sum value = Amount × (1 + net return)ⁿ
• SIP value = SIP × ((1 + i)ᵐ − 1) ÷ i × (1 + i), with i = net return ÷ 12

Tracking difference is how far a fund's actual return lags its index; it already includes the expense ratio when taken from factsheets, so enter one or the other consistently.

Worked example

These are the sample values already filled in the calculator above, and the result it returns for them:

Tips for using the Index Fund Compare Calculator

• Direct plans of Nifty 50 index funds typically cost 0.1–0.3% a year.
• Check tracking error as well — a cheap fund that tracks poorly can still underperform.
• ETFs can be even cheaper but need a demat account and have bid-ask spreads.