1893 Satanists were counted in the UK's National Census of 2011 despite "extensive coverage in the media"1 which make some suspect that numbers are higher. The number of Satanists is notoriously difficult to estimate. Most Satanic groups are informal, temporary and ad-hoc (so 'congregation' numbers cannot be counted), and the mainstream Church of Satan does not publish membership numbers. Also, many Satanists are not members of the Church of Satan. Hence, estimates of numbers of Satanists have varied wildly according to authors' imaginations and paranoias. In 2001 and 2002 I enquired at London Satanists meetings and found that only half identified themselves as a Satanist on the census. Others put "atheist" or even Christian denominations as their religion. This is a significant under-representation. As 1525 were counted in the 2001 Census, an estimate of 3050 seems sensible. Now in 2011, with slight growth in terms of percent of the population since 2001, an estimate of 3850 seems sensible2.
“As a rule, LaVey doesn't disclose membership figures. "If it's too low, we would be perceived as insignificant, and if it was too high we'd be considered too much of a threat and there would be reason to destroy us. [...] Besides, after 25 years, it would be very difficult to calculate our membership. Members are lifetime members; they don't have to pay any renewal fees every year so we have had a cumulative increase since 1966." Tom Wedge explains this phenomenon in his 1987 book, The Satan Hunter: "However, it must be realized that the great preponderance of the followers of the Church of Satan have never formally made an effort to actually 'join' the church.”
Dave Evans in 2001:
The researcher Dave Evans from the University of Bristol suspects a figure lower than my 3050 for the 2001 statistics, and humorously comments on the apparent attraction of Satanism for academics and social psychologists:
“Satanists are nowhere near as populous as might be believed from fundamentalist claims, and as remarked above, if the total number of 'serious' Satanists in the UK is over 3,000 that would be hugely surprising. Fundamentalist claims otherwise are largely nonsense, only designed to create panic, based on fundamentalist notions. [...]
My own work leads me to believe that there might actually now be more academics researching occultism in general in the UK than there are Satanists practicing their version of it. Both numbers are low.”