/cohort-analysis

Retention Metrics Glossary

Definitions for retention metrics used in cohort analysis. Use these as the canonical definitions when writing reports.

Core Retention Metrics

Day-N / Week-N / Month-N Retention

The percentage of users from a cohort who were active on (or within) period N after joining.

N-period Retention = (Users active in period N) / (Cohort size at period 0) × 100

Variants:

• Unbounded (on or after): User is retained if they were active any time up to period N
• Bounded (exactly at N): User is retained only if they were active within period N (the standard definition)

Always specify which variant you're using.

D1 / D7 / D30 Retention (Day-based)

Common benchmarks for consumer apps. Measured using bounded windows.

Benchmarks vary widely by product type — use industry-specific sources.

Rolling Retention

A user is counted as retained in period N if they were active at any point from period N onwards.

Rolling Retention (N) = Users who returned on period N or later / Cohort size

Rolling retention never decreases — it can only stay flat or increase as you extend the window. Useful for showing "did this user ever come back?"

Week-over-Week (WoW) Retention

Percentage of weekly active users from week N who are also active in week N+1.

WoW Retention = WAU(this week) who were also WAU(last week) / WAU(last week)

Month-over-Month (MoM) Retention

Same concept for monthly active users.

MoM Retention = MAU(this month) who were also MAU(last month) / MAU(last month)

Revenue Retention Metrics

Gross Revenue Retention (GRR)

The percentage of recurring revenue retained from existing customers, excluding expansion.

GRR = (Starting MRR − Churn MRR − Contraction MRR) / Starting MRR × 100

GRR is capped at 100% (cannot exceed starting revenue).

Best-in-class: > 90% for SaaS; > 85% for SMB-focused SaaS.

Net Revenue Retention (NRR) / Net Dollar Retention (NDR)

Revenue retained including expansion (upsell/cross-sell), minus churn and contraction.

NRR = (Starting MRR − Churn MRR − Contraction MRR + Expansion MRR) / Starting MRR × 100

NRR can exceed 100% if expansion outweighs churn.

Best-in-class: > 120% for enterprise SaaS; > 100% for any healthy SaaS.

Logo Retention / Customer Retention Rate (CRR)

The percentage of customers (accounts, not revenue) retained over a period.

CRR = (Customers at end − New customers acquired) / Customers at start × 100

Derived Metrics

Churn Rate

Monthly Churn Rate = Churned customers this month / Customers at start of month × 100

Relationship: Monthly Retention Rate + Monthly Churn Rate = 100%

Expected Lifetime

Expected Lifetime (months) = 1 / Monthly Churn Rate

Example: 5% monthly churn → 20-month expected lifetime.

Lifetime Value (LTV) via Retention

LTV = ARPU × (1 / Churn Rate)   [for constant churn rate]

Period Labels Explained

Period 0 should always be 100% unless there is a data quality issue (users who had the retention event before their cohort date).