Formula and the right denominator
Conversion rate = conversions / visits × 100. Everything depends on the denominator. Google Ads divides conversions by ad interactions: 50 conversions from 1,000 clicks is 5%. GA4 offers a session-based rate and a user-based rate, which give different results for the same site.
Google Ads notes that with several conversion actions, or with Every counting, the rate can exceed 100%, since one interaction can produce several conversions. For a readable metric, calculate it on a single primary action.
Why it varies so much
Conversion rate depends first on visitor intent. A search for your brand name converts far better than a click from a social feed. It also varies with device, price, the commitment you ask for (a call converts less than a free download) and season.
It drives ad profitability directly: CPA = CPC / conversion rate. At the same cost per click, going from 2% to 4% cuts cost per conversion in half. It is often the cheapest lever in a Google Ads account.
Levers to improve it
Before changing anything, make sure the rate is measured correctly: a conversion tag firing twice or on the wrong page inflates the rate and makes every test look like a win.
- Keep the exact promise of the ad or link on the page.
- One primary call to action, visible without scrolling.
- A form trimmed to the fields you truly need.
- Concrete proof near the button: reviews, past work, guarantees, timelines.
- A fast mobile page, since mobile often brings most of the visits.
- A/B tests on one element at a time so each gain is measured.
