Click-through rate (CTR) is the share of impressions that lead to a click. Google Search Console calculates it as clicks divided by impressions. A click counts when it takes the user to a page outside Google Search, Discover or News. You find the figure in the Performance report, per query and per page.
Example
Say a page about boiler servicing appears 2,000 times in search results in a month and gets 60 clicks. The CTR is then 60 divided by 2,000, or 3 per cent.
Why does it matter?
A low CTR with many impressions means people see your result but do not click it. Sometimes a clearer title tag or meta description that matches the question better helps. Sometimes it comes down to what else is on the results page, such as an AI Overview or other prominent results above yours.
Common mistake
Comparing CTRs across different queries at face value. Your position, the kind of question and the layout of the results page differ per query. Someone searching for your business name behaves differently from someone with a general question. Compare per query and per period instead.
How do you check it?
In Search Console, open the Performance report, switch on Average CTR and group by queries or pages. How AI Overviews change the search results is covered in AI Overviews and AI Mode: what do they mean for your website?