Google CTR SEO Algorithm
We’ve been working on an algorithm this morning to give (rough!) estimates of click-throughs on a given ranking and monthly traffic volume.
Click-through rates vary wildly across different types of search terms and indeed, different types of searches so we’ve used a relatively basic average for the purpose of this calculation, using publicly available data on Click-Through rates from various sources.
This is far from being a golden rule that can be followed indefinitely and it will be out of date within 2 months due to the way Google works and how people use search changing over time, however for the meantime it is a good guide to use to get an estimate based on industry averages of how many clicks it should be possible to get for a given rank and search volume.
The Formula
1 / ((Google Rank1.1) * 5)
The formula above gives the above CTR graph – it also provides for easy ways of adjusting the curve to match changes in search patterns. By changing the 5 to a higher number, you can change the graph to reflect lower CTRs across rankings. By changing the 1.1 you can adjust the drop-off as you move down the rankings.
Example Usage
If we take the search term “web design” as an example, we can see that there are 246,000 monthly global searches for this term (source: Google Adwords). If we plug this data into the above equation and ask it to estimate how much traffic we would get if we ranked fifth on Google for this term, the calculation would look as follows:
246,000/((5^1.1)*5) = 8,377
This gives us an estimated monthly search click-through of 8,377.
If we adjust this calculation for 3rd place it would look like this:
246,000/((3^1.1)*5) = 14,694
It’s pretty easy to use as a general benchmarking estimation tool.
Summary
As stated above, this technique and algorithm is not scientifically perfect, however the differences in results, CTRs across terms and how people use them will introduce more error into this calculation than the shortcomings of this formula so it is still useful in estimating click-throughs at different ranks for a given search volume and is useful for highlighting potential issues.
If your CTR is below average then this may indicate an issue with the way your Title and Description is shown on Google, for instance, or it may indicate that competing search terms have got the answer to a query nailed down better than you have.