Cohort Analysis Calculator

This calculator tracks a single cohort's retention across three months, computing each month's retention rate as that month's retained users divided by Initial Users, times 100 (lines 10-12). Initial Users and each month's own Retained count have closely matched effects on that month's retention rate — both are real, verified drivers, with Initial Users showing a marginally larger measured effect purely from the mild convexity of dividing by a changing denominator, not from the formula weighing it more heavily. Initial Users, however, clearly dominates Average Retention Rate, since it sits in the denominator of all three monthly retention terms at once, while each month's Retained count only affects its own single term.

Average Revenue per User has no effect at all on any retention or churn rate — it only enters Estimated LTV and Observed Cohort Revenue, both of which it dominates, since it's a flat multiplier applied to the whole cohort at once rather than to any single month's user count. Estimated LTV assumes a constant average monthly churn rate projected forward indefinitely, capped at 36 months when churn computes to 0 (line 30) — this calculator does not account for a retention curve that flattens out or declines non-linearly over a customer's lifetime, which real cohorts very often do after the first few months.