PostHog Handbook Library / Growth

388 words. Estimated reading time: 2 min.

Retention metrics

We use Net Dollar Retention (NDR) and Gross Dollar Retention (GDR) to track how well we're retaining and growing customer revenue over time. We use adjusted revenue to calculate these retention metrics for a more accurate picture of our business. This way, we get clearer signals about retention by removing the noise from spikes, trials, and organizational shifts.

How we calculate

We use a rolling time period approach that compares customer revenue from a base month to the current month:

NDR (Net Dollar Retention)

NDR shows total revenue retention including expansions, contractions, and churn.

Formula: Sum(current_month_mrr) / Sum(base_month_mrr)

If NDR > 100%: We're growing revenue from existing customers (expansions outpace contractions/churn) If NDR = 100%: We're maintaining the same revenue from existing customers If NDR < 100%: We're losing revenue from existing customers

GDR (Gross Dollar Retention)

GDR shows how much of our base revenue we're retaining, without counting expansions.

Formula: Sum(MIN(current_month_mrr, base_month_mrr)) / Sum(base_month_mrr)

GDR caps each customer's current revenue at their base month amount so it only measures downgrades and churn.

Why $5K+ ARR customers?

Why rolling retention?

Cohort based retention for lifecycle insights

We also track cohort based GDR and NDR as well as cohort based usage retention to:

Canonical URL: https://posthog.com/handbook/growth/revops/retention-metrics

GitHub source: contents/handbook/growth/revops/retention-metrics.md

Content hash: 0d093d6322bcbb76