How are Visiting and Domestic tourists calculated?

I'm trying to attain a culture victory, so I know that tourism is important. In order to win, the number of Visiting Tourists must be greater than the Domestic Tourists of all other civilizations.

How are these numbers calculated? The Civilopedia only talks about sources of tourism, not how this translates into numbers of tourists.

Solution 1:

"It's simpler than you think really.

Culture and Tourism.

You win when you generate more Total Tourism than everyone's Total Culture.

So if everyone's Culture are as follow 3019 27931 371 12178

You win when you generate '27932' Tourism, as that will be more than the highest.

Since showing huge numbers such as 27931 makes it difficult to read, they simply divided all values by 100. In this case it would say 279 Tourists, and would tell you that you need 280 to win."

Via @Timmy Jim