As far as I know, it’s actual count. There is no real reason to do approximations. The only reason to do that is to use only a sample dataset, but Amplitude tends to run all the queries with full data set.

Is there a reason you suspect it is?

the Amplitude officer told us it’s an approximation. He did mention there are a list of custom formula which some are approximations, not actual count. So, I’m just asking around to get to know more. 

Hi @yingng,

This is Yuanyuan from the Amplitude Support team - thank you for writing in!
The custom formula (PROPCOUNT) is an actual count and it calculates the number of distinct property values for the property the event is grouped by. 

Please feel free to explore all the custom formulas in this article. 

Best, 

Hi  Yuanyuan Zhang,

Thanks for the clarification. Yeah, I did read the article before, it didn’t mention about PROPCOUNT is an estimation. 

Thank you. 

regards, 

Ying