Every time your ad is eligible to show, AdWords calculates its Ad Rank using your bid amount, components of Quality Score, and:
the daily budget you’ve set
your historical conversion rate
the expected impact of extensions and other ad formats
the search ranking of your website
Explanation:
A value that’s used to determine your ad position (where ads are shown on a page) and whether your ads will show at all. Ad Rank is calculated using your bid amount, the components of Quality Score (expected clickthrough rate, ad relevance, and landing page experience), and the expected impact of extensions and other ad formats.
Ad Rank is a value that’s used to determine your ad position. or whether your ads will show at all. AdWords recalculates this value each time your ad is eligible to appear and competes in an auction.
AdWords calculates Ad Rank using your bid amount, your ad quality (including expected clickthrough rate, ad relevance, and landing page experience), the Ad Rank thresholds, the context of the person’s search, and the expected impact of extensions and other ad formats.
When estimating the expected impact of extensions and ad formats, AdWords considers the ad relevance, clickthrough rates, and the prominence of the extensions or formats on the search results page. As a result, you can still win a higher position at a lower price with highly relevant keywords and ads.
Read more here: https://support.google.com/adwords/answer/1752122?hl=en
