Bracketed Retention
AdvancedBracketed retention measures return behaviour over multi-day ranges such as days 1 to 3 or 4 to 7 instead of individually numbered days.
The rule is simple: a user active on any day inside a range counts as retained for that range. This definition suits products whose usage rhythm is not daily and which look dead under a day-by-day measurement. What is often forgotten is that bracket width itself shapes the number, since wider ranges always look better and two curves built on different brackets are not comparable at all.
How it is calculated
Bracketed retention for a range = cohort users with at least one activity inside that range ÷ cohort size
The denominator is always the original cohort size, not the survivors of the previous range. A user active on several days inside a range is counted once, and ranges must not overlap. The unit is a percentage.