Ahrefs Rank aims at solving the same tasks as Google PR.
Imagine billions of pages with amazingly huge amount of backlinks.
If you have the possibility to register all of them together, then you have a chance to compare their mutual impact.
Ahrefs Rank measures the impact of all backlinks with different link juice to a given page. Every URL has its own AR.
Let's imagine the process of Ahrefs Rank building as a couple of steps or iterations:
- A downloaded page gives its rating to all pages it refers to (only dofollow links are counted);
- The rating value such a page adds depends on its own rating and the number of links it has.
For example, Page has the rating of 100 and 10 dofollow links.
Page can pass no more than 80% of its rating to another page.
That is, Page with the rating of 100 passes the rating of 80.
This rating 80 is divided between 10 dofollow links, each link will get the rating of 8.
This procedure is repeated many times for every page and, thus, the rating is spread over the link net. We also take into account internal links for the rating calculation.
In general, the more backlinks a given URL has itself - the higher AR score it receives and more link juice it has in backlinking to others. But having one "fat" link can give more juice in AR than a hundred of "thin" backlinks.
When you analyze backlinks in a report, you see the rounded AR of every backlink you have.
The important thing is that Ahrefs Rank takes into account and cuts out the "confusing loops", when sites link to each other in the form of a circle and send each other high score again and again and again.
As a result of such loops, the score could become higher and higher until it turns unreal. That's why it is important to recognize them and take into account.
As the backlinks database is constantly updated, AR is also updated to include the latest changes.
We have one absolute advantage over Google's PR: AR shows the objective mathematical information you can work with. It depicts an authority of a page without any manual impacts.
Ahrefs Domain Rank (ADR) is built under the same principles.