The Nifty 50 index is calculated using the free-float market capitalisation weighted method. Free-float market cap means that only those shares of the company that are freely available for trading by the public will be taken into account. The shares that are locked-in, such as those held by promoters or the government, are not factored in.
Check out the steps involved in calculating the Nifty 50 index below.
Step 1: Calculation of market cap of each company
This is computed using the formula given below.
Market capitalization = (Shares outstanding) x (Current price per share)
Step 2: Calculation of the free-float market cap of each company
To compute the free-float market cap, you need to use the Investable Weight Factor, which shows you how much of a company’s total shares are available for trading freely on the exchange. The formula is as follows.
Free-float market capitalization = (Market capitalization) x (Investable weight factor or IWF)
Step 3: Calculation of the weighted free-float market cap of each company
Now, you need to use the weight assigned to each company in the index. You can use the formula given below.
Weighted free-float market cap = (Free-float market capitalization) x (Weight)
Step 4: Calculation of the current market value of each company
This is simply the sum of total weighted free-float market capitalization of all the stocks in the index.
Step 5: Calculation of the index value
Lastly, to calculate the index value, you need the base market capital, which is the benchmark used to compute the Nifty 50. It has been set at 1000, with a base capital of Rs. 2.06 trillion. The formula you need to use is as follows.
Index value = (Current market value/Base market capital) * 1000