Click through rate (CTR) is an online advertising model which is the ratio of users who click on a specific link to the number of total users who view an advertisement. The model is most commonly used to measure the success of an online advertising campaign as well as the effectiveness of email campaigns for a particular website. Click through rate (CTR) is the number of clicks that your ad receives divided by the number of times your ad is shown: clicks ÷ impressions = CTR. For example, if you had 6 clicks and 1000 impressions, then your CTR would be 0.6%. Use this online CTR calculator to estimate the success of your online advertisement for your website.