What is the number of people who practice Wicca in the UK?

Answer 1

The exact number of people cannot be determined because it is a secretive religion. However, some people have participated in studies. Quote:

An unidentified study in 1997 predicted that there were 100,000 practicing Neopagans in the United Kingdom. ThePagan Federation in the UK reported in 1999 that they were currently receiving 100 inquiries a month from potential new recruits

So, if we take the baseline 100,000, then add 100 time the number of months between 1997 and 2010, you come up with a baseline number of 115,600. But such a number is extremely low if you look at the number of Wiccans/Pagans in the US.

"Specifically, the number of Wiccans more than doubled from 2001 to 2008, from 134,000 to 342,000, and the same held true for [other] neo-pagans, who went from 140,000 in 2001 to 340,000 in 2008."

.....

With 682,000 subjects admitting that they were Wiccans or other Neopagans, the true number would probably be considerably larger than this number.

That is just the numbers in the US. If you consider that there is another 200,000 in the UK alone, Wicca/Paganism would have surpassed Hinduism in number of followers.