How accurate is Google Play installs measure? When you look at app listing in Google Play there is "Installs" section:



How accurate is that? What values can be found there? Does is take uninstalls into consideration?
It doesn't take uninstalls into account. It is very slow to update and based on the all-time number of individual Google accounts that installed it, NOT the devices. 

That's all based on what I experienced, from the Play Console combined with Store

Possible values include:

1+

5+

(Maybe some more)

100+

500+

1k+

5k+(?)

10k+

50k+

100k+

(Maybe some more)

1m+

(Maybe some more)

1b+