CTR (click-through rate)
Also known as: Click-through rate, Clickthrough rate
In short
The percentage relationship between recorded clicks and impressions for an ad, listing or other measured item in a defined reporting scope.
Measure response to an impression
Click-through rate expresses how many clicks were recorded relative to impressions. Calculate it as clicks ÷ impressions × 100 for the same item, date range and measurement system.
CTR concerns recorded events, not necessarily unique people. A person can generate multiple impressions or clicks. Also check what a platform counts as a click: reports may distinguish all clicks from clicks that lead to a destination.
The comparison context matters. Search and display placements have different behavior, and branded queries may attract a different response from broad discovery traffic.
Illustrative calculation
Imagine a fictional product ad receiving 360 clicks from 12,000 impressions during a week. Its CTR is 360 ÷ 12,000 × 100 = 3%.
To combine it with another ad, sum both ads’ clicks and impressions before calculating the rate. An unweighted average of their displayed CTRs can be misleading when their impression counts differ.
Follow the journey beyond attention
A higher CTR indicates more measured clicks relative to delivery, but it does not establish purchase intent, completed orders or profit. Check whether the ad’s promise matches the landing page and whether the resulting traffic completes the intended action. Avoid treating a CTR improvement as a business improvement without those supporting outcomes.