Basics · also called CTR, click-through rate
CTR (click-through rate)
CTR (click-through rate) is the percentage of ad impressions that result in a click, calculated as clicks divided by impressions, multiplied by 100.
Click-through rate tells you how often people who see an ad click on it. If an ad is shown 10,000 times and clicked 50 times, the CTR is 0.5%.
CTRs differ hugely by channel. Search ads, which appear when someone is actively looking for something, usually have far higher CTRs than display banners, which interrupt someone reading an article. In search, CTR also feeds into platform ranking signals like Quality Score, so a better CTR can lower your CPC.
CTR is a useful signal but a poor goal on its own. A high CTR can come from accidental taps on mobile, misleading creative or click fraud; a suspiciously high CTR with no conversions is a classic warning sign of bots. Brand campaigns, CTV and DOOH often have no clicks at all, so they are judged on reach, viewability and incrementality instead.
Think of it like this
CTR is like the share of people who pick up a free sample after walking past a stand: interesting, but it does not tell you who bought the product.
An example
A banner earns 120 clicks from 60,000 impressions: CTR = 120 ÷ 60,000 × 100 = 0.2%. A search ad with 300 clicks from 5,000 impressions has a 6% CTR.
Related terms
CPC (cost per click)
CPC (cost per click) is a pricing model where the advertiser pays only when someone clicks the ad, and also the average amount paid per click.
Impression
An impression is one instance of an ad being served and counted as displayed to a user; it is the basic unit that most online advertising is bought and sold by.
Conversion
A conversion is a valuable action that an advertiser wants people to take after seeing or clicking an ad, such as a purchase, sign-up, app install, call or form submission.
Quality Score
Quality Score is Google Ads' 1-to-10 diagnostic rating of how relevant and useful a keyword's ads and landing page are, based on expected click-through rate, ad relevance and landing page experience.
Click fraud
Click fraud is generating fake or worthless clicks on pay-per-click ads, by bots, paid people or malware, to drain an advertiser's budget or inflate a publisher's earnings.