What Are Average Backlink Metrics and How Do We Calculate Them?

You might have come across the avg_backlinks_info object in the responses of DataForSEO Labs API. It returns average backlink metrics for the pages ranking for each keyword, and it can be found in the following endpoints:

• Keyword Ideas;
• Keywords For Site;
• Related Keywords;
• Keywords For Categories;
• Keyword Suggestions;
• Top Searches;
• Keyword Overview;
• Ranked Keywords;
• Domain Intersection;
• Page Intersection.

Here is what the object looks like:

{
  "avg_backlinks_info": {
    "se_type": "google",
    "backlinks": 23.428571428571427,
    "dofollow": 16.714285714285715,
    "referring_pages": 22.714285714285715,
    "referring_domains": 14.857142857142858,
    "referring_main_domains": 13.714285714285714,
    "rank": 124.42857360839844,
    "main_domain_rank": 573.4285714285714,
    "last_updated_time": "2022-07-29 15:30:40 +00:00"
  }
}

In the following paragraphs, we explain what this object is about, how its metrics are calculated, and what rank means across our APIs. If you’re benchmarking keywords against a backlink checker you already use, you’ll also find how each averaged field lines up with familiar Ahrefs metrics like Domain Rating and referring domain counts.

What are average backlink metrics and how are they calculated?

The avg_backlinks_info object returns the average backlink-related metrics calculated for the top 10 webpages ranking organically for the returned keyword. These metrics can give an SEO expert a sense of how competitive a certain keyword is so that they can estimate their chances to rank in the top 10 organic search results for it.

The object provides the following data:

• backlinks — average number of backlinks among the top-10 webpages;
• dofollow — average number of dofollow links;
• referring_pages — average number of referring pages;
• referring_domains — average number of referring domains;
• referring_main_domains — average number of referring main domains;
• rank — average page-level rank of the top-10 webpages (learn more about Rank and how it is calculated in this help center article);
• main_domain_rank — average rank of the main domains those webpages belong to.

To provide the avg_backlinks_info, we first take individual backlink-related metrics for each webpage from our database. Then we calculate the arithmetic mean. For instance, if page A had a rank of 234, page B had a rank of 350, and page C had a rank of 443, the average rank would be calculated as follows: (234 + 350 + 443) / 3 = 342.333333333

Comparing these averages with your own page’s numbers can show how far you are from the current top 10. Since rank and main_domain_rank come from our Backlinks API, it helps to know how that metric works.

How average rank values connect to Backlinks API fields

Both rank fields in the avg_backlinks_info object come from our Backlinks API. Here, rank is the average page-level score of the top-10 URLs, and main_domain_rank is the average score of the root domains those URLs sit on. Both are link-based authority scores built on the PageRank formula, using a damping factor of 0.5.

Inside Backlinks API, you’ll meet the same score under three field names:

• rank — scores the target in your request or, depending on the endpoint, the share of authority that a link, a referring site, or an anchor sends to that target;
• domain_from_rank — scores the website a backlink is placed on;
• page_from_rank — scores the specific URL a backlink is placed on.

To keep things straightforward: the first field looks at the receiving end of a link, and the other two look at where the link originated from. The Backlinks endpoint returns domain_from_rank and page_from_rank for every link it lists.

Domain scores are built from page scores and then compressed logarithmically. As a result, gains get progressively more expensive toward the top of the range: a domain sitting at 500 needs far more authoritative links to add a single point than a domain at 100. For the formula, the link types that pass or block authority, and the score conversion to 0–100 scale, see our guide to Rank, Domain from Rank, and Page from Rank in Backlinks API.

How average backlink metrics map to Ahrefs metrics

Here’s how the fields above line up with common backlink checker API fields, such as Ahrefs metrics, that you may already use in your product or reports.

The avg_backlinks_info object averages the top-10 results for a keyword. When you need the same number for a single site or URL, for example as a Domain Rating alternative, the Backlinks API returns it per target.

Some values won’t compare one to one:

• The averages in this object use our 0–1000 range, as the sample above shows, and DR tops out at 100. Backlinks API requests return 0–100 values if you set rank_scale to one_hundred, but the numbers still won’t match DR because the two scores are calculated differently;
• referring_domains counts blog.example.com and example.com as two sources, while referring_main_domains merges them into one. Use whichever matches how your product counts today (here’s an example with dofollow links);
• Endpoints such as Referring Domains score only the authority a site passes to your target through its links, so the same site can show a different value there than in Summary (see an example).

If you need an API for pulling referring domains and anchor text, Summary and Referring Domains return the domain counts, and the Anchors endpoint is our anchor text API.

Related Backlinks API metrics

• Rank metrics in Backlinks API — the formula, link types, and the rank_scale conversion;
• Rank differences across endpoints — how a single site can return several scores;
• Spam Score — the 0–100 spam metric for targets and backlinks;
• Dofollow referring domains and backlinks — how subdomains are counted in referring domain totals.

 
Our documentation lists every Backlinks API response field by endpoint: See Docs.