We calculate Keyword Difficulty by analyzing the search results and the backlink profiles of the pages already ranking in the top 10 Google results for the keyword. The stronger and more established those pages are, the higher the score.

We calculate Keyword Difficulty in three steps:

1. SERP Analysis. We start by analyzing the pages already ranking in the top 10 Google search results for the keyword. Three authority signals carry most of the weight of the formula:

Number of referring domains pointing to ranking pages (41.22%). A referring domain is a unique website that links to a page. The more unique sites linking to the pages on page one, the harder the keyword is to rank well for. Authority Score of the ranking domains (16.99%). Authority Score is Semrush's 1–100 measure of a website's overall SEO strength and credibility. If most of the top 10 come from high-authority sites, the keyword is harder to compete for. Dofollow to nofollow link ratio for ranking pages (9.17%). Dofollow links pass SEO value to the linked page, but nofollow links don't. When the top results carry a high share of dofollow links, the keyword is harder to rank for. 2. Keyword Parameters. Next, we factor in qualities of the actual keyword itself, including search volume (9.47%) and the SERP features triggered by the query. These include featured snippets (4.74%), instant answers (4.07%), branded results (3.50%), local packs (3.39%), knowledge panels (2.71%), top stories (2.03%), "People also ask" boxes (1.36%), and site links (1.36%). Longer keywords (-2.24%) and queries that result in no SERP features (-8.59%) tend to be easier to rank for.

3. Regional Calibration. Finally, we weight the score against the regional database it sits in. This prevents inflated or deflated scores in countries with varying search demand.

We regularly recalculate and update our Keyword Difficulty metrics as the ranking pages and SERP layouts change, so the score always reflects the current competitive landscape.