At a glance
D30 Retention % is a retention metric tracked from PostHog data. It measures the share of users who came back and were active 30 days after their first visit. PostHog builds it from cohort retention analysis, following each cohort of first-time users forward in time. D30 is the long-horizon read on whether your store earns a place in customers’ lives, and a low figure means acquisition is not translating into lasting relationships.
| What it counts | The percentage of a cohort still active 30 days after their first activity. |
| Sample type | Backend API data from PostHog retention insights, refreshed on the standard data refresh. |
| Why it matters | D30 is the durability test. High acquisition with low D30 means you are filling a leaky bucket. It is a foundational input to customer lifetime value. |
| Reading the value | Compare against the prior period and your baseline. A figure below 15% is flagged as weak long-term retention. |
| Currency | percent |
| Time window | 90D vsP |
| Alert trigger | <15% |
| Sentiment key | ph_retention_d30 |
| Roles | owner, marketing |
Calculation
Calculated automatically from your PostHog data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.Worked example
A representative reading of D30 Retention % for a typical merchant on PostHog. Suppose a cohort of 5,000 first-time users from early in the period sees about 950 return and act on day 30, a D30 of 19%. After a loyalty programme launched on 01 Apr 26, the next cohort’s D30 rises to 24%, meaning more new customers are forming a lasting habit. If instead it fell below 15%, the alert would warn that acquisition is not converting into retained customers. Cross-reference D7 Retention for the early signal and New vs Returning Users for the mix. For deeper investigation, use Vortex Mind to trace upstream causes; for natural-language exploration, ask Ask Viq.Sibling cards merchants should reference together
| Card | Why merchants reach for it |
|---|---|
ph_retention_d7 | Retention sibling: the 7-day early signal. |
ph_stickiness | Retention sibling: DAU as a share of MAU. |
ph_new_vs_returning | Retention sibling: new-to-returning mix. |
ph_mau | Executive sibling: monthly active base. |
pos_returning_users | Audience sibling: returning users count. |
Reconciling against the vendor’s own dashboard
Where to look in PostHog’s own dashboard: In PostHog, open a Retention insight and read the day-30 column of the cohort grid. The percentage there should align with this card. The two biggest levers are the retention event chosen and whether retention is recurring or first-time based. Why the Vortex IQ value may legitimately differ:| Reason | Direction | What to do |
|---|---|---|
| Retention event. Counting “any event” versus a specific action changes the rate. | Variable | Match the retention event. |
| Recurring vs first-time. PostHog supports both retention types, which give different curves. | Variable | Confirm the retention type. |
| Cohort maturity. Recent cohorts have not yet reached day 30 and are excluded. | Variable | Use mature cohorts only. |