How is Google Quality Score Calculated? Complete Formula & Components

Understanding the Quality Score Formula

Google’s Quality Score calculation follows a specific mathematical formula that combines three critical components into a single rating between 1 and 10. The formula is: 1 + 1.75(LPE) + 2(Relevance + 1.75(CTR)) = Quality Score. This equation demonstrates that Google weights different factors differently, with Ad Relevance and Expected Click-Through Rate receiving the highest multipliers. Understanding this formula is essential for anyone running paid search campaigns, as Quality Score directly impacts both your cost per click and your ad position in search results. The formula reveals that Google prioritizes relevance and user engagement signals above all else, reflecting their commitment to showing the most useful ads to searchers.

The Three Core Components of Quality Score

Expected Click-Through Rate (eCTR)

Expected Click-Through Rate represents Google’s prediction of how likely users are to click on your ad based on historical performance data and keyword-to-search-query matching. This component carries a multiplier of 1.75 in the Quality Score formula, indicating its significant importance in the overall calculation. Google analyzes your account’s historical click patterns for exact keyword matches to determine this metric, meaning that changing keyword match types will not directly impact your eCTR rating. The eCTR is calculated from actual user behavior, making it one of the most objective components of Quality Score. If you notice a dash ("—") in the eCTR column within Google Ads, it simply means your keyword hasn’t accumulated enough search volume data for Google to make an accurate prediction.

Ad Relevance

Ad Relevance measures how closely your ad copy aligns with the keywords you’re bidding on and the search queries users are entering. This component is multiplied by 2 in the Quality Score formula, making it the most heavily weighted factor in the calculation. Google evaluates whether your ad headlines, descriptions, and display URLs directly address what the searcher is looking for and whether they match your keyword intent. High Ad Relevance scores indicate that your ad messaging is tightly connected to your keyword selection, which improves user experience and click-through rates. Creating specific ad groups with tightly related keywords allows you to craft highly relevant ad copy that speaks directly to each audience segment, significantly boosting this component of your Quality Score.

Landing Page Experience (LPE)

Landing Page Experience evaluates the quality and relevance of the webpage users land on after clicking your ad. This component is multiplied by 1.75 in the Quality Score formula and encompasses multiple technical and content-related factors. Google assesses page load speed, mobile responsiveness, content relevance to the ad and keyword, transparency of business information, and overall user experience signals. A high-quality landing page should directly address the promise made in your ad, load quickly on all devices, and provide clear value to the visitor. Pages with poor loading times, misaligned content, or confusing navigation will receive lower Landing Page Experience ratings, which directly reduces your overall Quality Score and increases your cost per click.

Quality Score Impact on Campaign Performance

The relationship between Quality Score and cost per click is inverse and substantial. A keyword with a Quality Score of 10 can achieve the same ad position as a competitor’s keyword with a Quality Score of 5 while paying significantly less per click. This cost advantage compounds over time, making Quality Score optimization one of the most cost-effective strategies for improving PPC campaign profitability. Additionally, higher Quality Scores often correlate with better ad positions, increased visibility, and improved click-through rates, creating a positive feedback loop that benefits your entire campaign performance.

How Google Determines Quality Score Components

Google’s evaluation process for each Quality Score component relies on sophisticated machine learning algorithms and historical data analysis. For Expected Click-Through Rate, Google examines your account’s historical performance for exact keyword matches, considering factors like ad position, device type, and geographic location. The system learns from millions of search queries and user interactions to predict future click behavior with remarkable accuracy. Ad Relevance assessment involves natural language processing to understand the semantic relationship between your keywords, ad copy, and search queries, ensuring that the meaning and intent align properly. Landing Page Experience evaluation includes automated crawling of your landing pages to assess technical performance metrics, content quality, mobile usability, and security signals like HTTPS encryption.

Strategies to Improve Your Quality Score

Improving Quality Score requires a systematic approach focused on the three core components. Start by conducting thorough keyword research to build campaigns on a solid foundation, ensuring that your keywords are highly relevant to your business offerings and user search intent. Organize your keywords into small, tightly related ad groups—ideally 5-20 keywords per group—so you can create specific, targeted ad copy that directly addresses each keyword’s intent. A/B test your ad copy continuously, testing different headlines, descriptions, and calls-to-action to identify messaging that resonates with your target audience and drives higher click-through rates. Optimize your landing pages for speed by compressing images, minimizing code, and leveraging browser caching, as page load time is a critical ranking factor. Ensure your landing page content directly matches the promise made in your ad and the keyword intent, avoiding generic pages that don’t address the specific user need. Implement mobile-responsive design to provide an excellent experience across all devices, as mobile users represent a significant portion of search traffic. Finally, maintain account hygiene by regularly reviewing and pausing underperforming keywords, removing irrelevant keywords that don’t align with your offerings, and consolidating similar keywords to improve relevance.

Quality Score vs. Other Performance Metrics

While Quality Score is important, it’s crucial to understand that it’s just one component of overall campaign success. Cost per click, conversion rate, cost per conversion, and return on ad spend are equally important metrics that should guide your optimization strategy. A keyword with a lower Quality Score might still be profitable if it drives high-quality conversions at a reasonable cost. Conversely, a keyword with a perfect 10/10 Quality Score might not be worth bidding on if it doesn’t convert users into customers. The key is to balance Quality Score optimization with your broader business objectives, using Quality Score as a tool to improve efficiency rather than as an end goal in itself. Many successful advertisers focus on keywords that achieve a Quality Score of 6 or higher while maintaining strong conversion metrics, rather than obsessing over achieving perfect 10/10 scores across the board.

Quality Score Limitations and Considerations

Quality Score has several important limitations that advertisers should understand. The metric is based on historical data for exact keyword matches, meaning new keywords won’t have a Quality Score until they accumulate sufficient search volume and click data. Seasonal variations in search behavior can cause Quality Scores to fluctuate throughout the year, particularly for keywords related to seasonal products or services. Quality Score doesn’t directly measure conversion quality or business value—a high-scoring keyword might attract clicks from users who aren’t ready to purchase. Additionally, Quality Score is specific to Google Ads and Microsoft Ads; other advertising platforms use different quality metrics or scoring systems. Understanding these limitations helps you use Quality Score appropriately as one tool among many in your PPC optimization toolkit, rather than relying on it as the sole indicator of campaign health.