UX Glossary · C
Conversion rate
Also: CVR
The proportion of people who complete a defined action out of those who could have.
Conversion rate is completions divided by opportunities, expressed as a percentage. The “conversion” can be any defined action: a purchase, a sign-up, a form submission, a download.
The denominator is where the arguments happen
The number is only meaningful once you say what it is a proportion of. Purchases over all site visitors, over sessions that reached a product page, and over sessions that started a checkout are three very different figures, and all three get called “conversion rate”.
Comparing your rate to an industry benchmark is close to useless for this reason, since you rarely know how the benchmark was calculated.
What moves it
Rates go up for reasons that have nothing to do with design. A campaign bringing better qualified traffic raises conversion without a single interface change. A discount raises it and lowers margin. Segmenting by traffic source is usually the first honest step.
In practice
Two habits keep it useful. State the denominator every time you quote the number. And report the change as it was measured, “from 2.1% to 3.8%”, rather than converting it into a relative figure like “an 81% uplift”, which sounds far larger and is the same fact.