Method of calculating Sensex

Senex is calculated using a market capitalization of free-floating, taking into account the overall proportion of shares that are actually available in the market. The value of the index at a given point represents the market value of freeflotation of the 30 securities that comprise it in relation to a year and a base value (1978 -- 79 = 100) First, it calculates the market capitalization of each company constituents by multiplying the number of shares outstanding by the price in the market, it weighs the weight of each company in the market. The result is applied a factor to get the free float market capitalization of free flotation, which is divided by An index divisor to link it to the base year and thus be able to make comparisons, obtaining the value of the SENSEX

As mentioned earlier, the index takes into account the actions that are actually on the market, not including: 

- The belonging to or founding directors that include elements of control

- The people or companies with interests in control 

- The government as a sponsor or buyer 

- The route acquired by foreign investment 

- The shares of strategic corporate or individual institutions

 - Capital owned by associations, companies or groups of Foundations

The BSE determines the free-float factor to be applied based on detailed data companies must submit. So you get the percentage of market capitalization that are considered for the construction of the index. Finally divisor factor applied to the base 1978-79 = 100.