The World Christian Encyclopedia and Operation World both track denominations in the world.Some have looked at the (in 2015, estimated) 45,000 denominations in the world and decry this as an example of a lack of unity.
And that may be true.
But let me just point out the fine print: as statistical units, denominations are counted by country.
There are 239 countries.
So, for example, the Roman Catholic Church counts as 239 denominations.
(Likewise with Anglicans and Orthodox; and many mainline Protestant denominations.) (This is well documented in the statistical notes of the tables, but often overlooked.) So, taking 45,000 denominations, divide by 239, and you have an average of 188 denominations per country. In countries that have hundreds of millions of people (or billions), this really doesn’t seem all that odd, after all.