About
ProductMetrics is a reference for the metrics product and growth teams actually use: definitions, formulas, benchmarks, and the major measurement frameworks, each on its own page. It's public, read-only, and free to cite — no ads, no signup, no tracking wall. It's built to be a source that both people and AI agents can quote with confidence.
What this is
The catalog currently covers 44 metrics and 4 measurement frameworks. Every entry gives a plain definition, the formula, what the number actually measures, what to watch for, and how it connects to related metrics — the working detail a PM needs to use the metric, not just recognize the term. The goal is a single canonical place to look something up, link to, and reason from, rather than a blog post you read once.
Who maintains it
ProductMetrics is maintained by Roarke as a one-person editorial project — a single person reading primary sources, writing the entries, and standing behind them, rather than a crowd-edited wiki. That keeps the voice and the bar for inclusion consistent. .
How metrics are selected
The catalog aims for coverage of the AARRR funnel — acquisition, activation, retention, revenue, and referral — alongside Core Web Vitals and the behavioral and health metrics teams lean on to make decisions. The bar for inclusion is “widely used and decision-relevant,” not exhaustive. A metric earns a page when knowing it changes what a team would do; obscure or purely academic measures are left out on purpose.
Canonical vs. composite
Most entries are industry-standard metrics with established, broadly agreed definitions. A few — currently 4 of them, the composite scores like session, navigation, engagement, and frustration score — are emerging, tool-defined analytics scores: genuinely useful, but not industry standards, because the exact formula varies by the tool that computes it. Those carry a “Composite” badge and a disclaimer on their pages so you never mistake a vendor score for a settled definition. Stating that plainly is the policy, not a footnote.
Cited, reviewed, open
Company-specific claims and benchmark figures carry source citations and a last-reviewed date — benchmarks were last reviewed in June 2026. The same data is mirrored as a read-only JSON API, an /llms.txt for agents and crawlers, and an MCP server, so a tool can pull the exact same definitions and citations the pages show — all published under a Creative Commons Attribution 4.0 license, free to reuse and cite with attribution. If a figure or definition looks wrong, corrections are welcome — the point is to be right, not to be the last word.
Contact & corrections
Spotted an error, an out-of-date benchmark, or a missing citation? Email team@productmetrics.org or send feedback via the widget in the bottom-right of any page. Corrections that improve accuracy are the most valuable contribution this site can get.