How Google determines Quality Scores has always been a bit of a dark hole – not completely black mind you – but close enough. We can (and have) speculated on the numerous factors and how they are weighted but nothing has ever been definite.

Recently however Google made changes to its API that allowed researchers to gain valuable insight into three key Quality Score factors. These being “expected click-through rate”, “ad relevance” and “landing page experience”.

This new version of Google’s API allows you to download each of these three Quality Score factors along with its status (average, below average, above average) for every search keyword in an account. So you can now analyze at scale exactly how Google weights the sub-factors and determines visible Quality Score.

Even if you do not have access to the API you can still determine QS although the process would be a bit time consuming not to mention tedious. But just having the below information will help gain you deeper insight into why your Quality Score is what it is.

The formula is: 1 + Landing Page Experience weight + Ad Relevance weight + CTR weight.


Landing Page ExperienceAd RelevanceCTR
Above average3.523.5
Below average000

For instance let’s say you have these factors:

Landing Page Experience: average — 1.75 points
Ad Relevance: above average — 2 points
CTR: average — 1.75 points

Your Quality Score is: 1 + 1.75 (LPE) + 2 (Relevance) + 1.75 (CTR) = 6.5. As Google doesn’t show fractions, this is rounded to a 7, which is seen inside your account.

Armed with this information you can more easily assess why you are seeing low Quality Scores and what area(s) you need to work on to improve them.