The UK’s Office of Work and Pensions estimates that a child born today has a 30% chance of reaching the age of 100. In contrast, a person 80 years old today has only a 7.7% chance of reaching the age of 100. Indeed, a person today, according to these estimates, has to be about 96.5 years of age to have the same probability of reaching the age of 100 as a newborn.
You can find the data at The Guardian.
Hat tip: John Lanchester’s article on Marx in the LRB.