Nozzle has a very robust way of calculating clickthrough rate. Our calculation is made up of over 2,000 lines of code spread across 7 different files. Let’s take a look at what goes into our CTR calculation.
First, we look at several up-to-date CTR studies to create a solid CTR curve that we can use as the foundation for both branded and non branded keywords and for both desktop and mobile.
From there, we look at the individual SERP for each keyword looking to see if there are one or two columns, an ads section, or zero click features like dictionary results or direct answers.
We then assign a certain portion of the overall page clicks to the ads section, column 2 and to no click or zero click type results.
Next, we look at the size of each individual result in terms of size. More weight is given to listings with larger pixel coverage like featured snippets, video packs, image packs, People Also Ask, Top Stories, etc.
We assign clickthrough percentage to every link on the page. Even sitelinks and extra buttons, like the View All button pictured below, are assigned some percentage of the total page clicks.
Furthermore, certain items are weighted more according to their position within the pack. For example, People Also Ask questions at the top of the box are given more weight than those at the bottom, and videos or images on the left side of a pack are given more weight than those at the right.
All of these calculations are summed up and normalized so that each clickable item is given a realistic CTR.
See the image below for an example of CTR for a specific SERP. The no click or zero click CTR percentage we gave this page was 13%. The paid section was given 10%, column one 67.5%, and column two 9.5%.
Some CTR is assigned to the listings in column 2 and some to the ads. Scrolling down a ways, we assigned 0.1% to the highlighted sitelinks. Down further, the first local listing gets 0.9% clickthrough rate, and the next two get a 0.5%. The first top stories result gets a 0.9% clickthrough rate, the second gets 0.6%, and the third gets a 0.4%.
And that is how Nozzle comes up with highly customized CTR percentages for each individual result.