The steps can be like this:
- Divide Total Market Cap of Sensex Constituents by the total number of outstanding shares of the constituents. This will provide the numerator of the P/E ratio, i.e., price per share.
- Similarly, total the trailing earnings of all the constituents and divide the resultant sum once again with the total number outstanding shares of the constituents to get EPS, the denominator.
- Divide the numerator/denominator and you have the Sensex P/E ratio in hand.
A short-cut method is:
P/E = Market Cap/Total Earnings