Formulas let you build new KPIs from the data you already collect, without tracking extra data points or calculating them outside Countly. In Countly 27.0, a formula is a metric in Drill: an expression over the query's other metrics, which it refers to by their letters, such as B / A.
A formula is calculated for every time bucket and every breakdown group, so it follows the rest of the query. Where it would divide by zero, the cell stays empty.
Some examples of formulas you can build:
-
Share of a cohort: profiles in a "Pediatrics" cohort (A) against profiles in an "All appointments" cohort (B), as
A / B. -
Combined count: credit card applications (A) plus loan applications (B), each filtered to "Premier" customers, as
A + B. -
Conversion rate: completed upgrades (B) against visits to the pricing page, tracked as an event (A), as
B / A. -
Rate per session: workouts (B) per session (A), as
B / A.
To learn how to build queries and formulas in Drill, see: