How many people have the same date of birth as me?

On 05/08/2013 the world population is estimated to be 7,169,646,527

Assuming there is a random chance that people will be born on any day of the year and that there are 365.25 days in a year, then there will be:

7,169,646,527/365.25 or 19,629,422 people alive that share your birthday. That is over 19 and a half million.