Different countries count their population and map the religious landscape in different ways. This chapter compare and contrast the empirical ways in which population level religious adherence is recorded in Denmark and New Zealand. The purpose of this chapter is to provide a critical reflexive approach to national level religious diversity statistics by undertaking a comparison of affiliation data from Denmark and New Zealand. Where New Zealand measures adherence through its national population census and conversely, Denmark measures it through localized measurements. A clash between these ideas of uniform membership and the clear distinctions between different religions with what is a messier empirical reality is documented. It is demonstrated that the method/s chosen to collect national data have consequences for scholarship because the numbers produced both influence and construct the way in which we conceptualise religious diversity and the questions scholars ask of that data.