Index Growth Calculator

A stock market index tracks the performance of a group of stocks representing a market or sector. For example, the S&P 500 tracks 500 large US companies, while the FTSE 100 tracks the 100 largest UK-listed companies. You can't invest directly in an index, but index funds and ETFs replicate their performance very closely.

CAGR (Compound Annual Growth Rate) is the average annual growth rate of an investment over a period. It smooths out year-to-year volatility to show you what consistent yearly return would have produced the same end result. It's the most standard way to compare investment performance across different time periods.

This calculator uses adjusted closing prices, which include dividends that were reinvested. However, the results are shown in nominal terms (not adjusted for inflation). To get a rough inflation-adjusted figure, subtract ~2-3% per year from the CAGR.

Historical index data is sourced from Yahoo Finance and includes monthly closing prices. Data availability varies by index — most major indices have data going back to the 1990s, while some may have shorter histories.