SaaS Metrics

ARRR Funnel (Pirate Metrics)

ARRR is a product growth framework: Acquisition, Activation, Retention, Revenue, Referral. It helps pick the right KPI for each stage.

Updated 2026-01-23

Definition

ARRR is a product growth framework: Acquisition, Activation, Retention, Revenue, Referral. It helps pick the right KPI for each stage.

Example

A typical stack is CAC and signup rate (Acquisition), activation rate (Activation), 90-day retention (Retention), ARPA (Revenue), and referral rate (Referral).

How to use it

  • Use one primary KPI per stage to avoid metric overload.
  • Tie activation and retention to cohort outcomes, not vanity events.
  • Use referral as a signal of product delight, not just marketing reach.
  • Define a single activation milestone so teams align on success.
  • Review the full funnel monthly to keep trade-offs visible.

Common mistakes

  • Measuring stages with inconsistent definitions across teams.
  • Focusing on acquisition while ignoring retention (leaky bucket).
  • Optimizing one stage in a way that hurts another.
  • Treating the funnel as linear when product-led loops are present.

Why this matters

This term matters because small changes compound in SaaS metrics. Use consistent definitions by cohort and segment so you can diagnose retention, payback, and growth quality.

Practical checklist

  • Write a 1-line definition for "ARRR Funnel (Pirate Metrics)" that your team will use consistently.
  • Keep the time window consistent (weekly/monthly/quarterly) when comparing trends.
  • Segment results (channel/plan/cohort) before drawing big conclusions from blended averages.
  • Use a calculator that references this term (e.g., Activation Rate Calculator) to sanity-check assumptions.
  • Read the related guide (e.g., Activation rate: definition, formula, and how to improve activation) for context and common pitfalls.

Where to use this on MetricKit

Calculators

Guides