The 2011 UK Census provides the best possible estimate of the number of Scientologists in the UK, and a reasonable guide to the likely numbers in developed countries outside of the US.
It revealed that there were fewer than 2,418 Scientologists in England and Wales – an area which then had a population of 63.2 million people. This means that, in 2011, only one person in every 26,137 was a Scientologist.
That there are so few Scientologists in England (the home of Saint Hill Manor, where the founder of Scientology developed many of its doctrines and practices) is interesting n itself.
However, the full census data reveals more. By cross-referencing the results, the number of male and female Scientologists and their age profile can be seen