Introduction to SEO Formulas

Search Engine Optimization (SEO) is a field that demands constant monitoring, analysis, and informed decision-making of massive data and numbers of users visiting the website. To understand this amount of users coming on the website often SEO and Analytics experts use SEO formulas to interpret the behavior on the website. In this blog, we will talk about some of these formulas that an SEO professional should know.

1. Bounce Rate

Bounce rate is the percentage of our users who exit the website without any interaction or within 10 seconds. 

Formula: Bounce Rate = (Single Page Visits / Total Visits) * 100

If your website/app has a high bounce rate it might be an indication that you serving poor content, high load time, confusing UI/UX, and not enough CTAs on the website.

To understand the bounce rate I also like to calculate interacting users known as active users coming to the website. This is the number of users that are coming on the website calculated by the percentage of bounce rate and the number you receive is the number of leaving users. This you subtract with the number of total users. And you would receive the number of interacting users on the website.

Formula for Interacting/Active Users

Percentage of bounce rate calculated by users = Leaving Users, Users – Leaving Users = Interacting Users. Below is a hypothetical example of it. 

38.49% of 5,745 =  2,208.04, 5745 – 2208 = 3537. 

Speaking of interacting users, In the new GA4 model there are introduced a few new metrics such as engagement rate and engaged sessions.

2. Engagement Rate

Engagement rate is impacted by the percentage of users who interact with a web page. Users who do not find the page useful will leave without triggering events (remember that GA4’s data model is event-based). Events such as multiple pageviews clicks on the website, scroll, and goal conversions. Understanding these events would measure the engagement rate of your website/app. This metric is the exact opposite of the bounce rate. 

Formula: Engagement Rate = ((Engaged Sessions) / Sessions) * 100

A high engagement rate signals that your content resonates with your audience. It’s a crucial metric for assessing the effectiveness of your website’s content.

3. Keyword Density

Keyword density is a formula to calculate the percentage of times a particular keyword is to be repeated in a piece of content based on the word count. 

Formula: (Number of Times Keyword Appears / Total Word Count) * 100

Balancing keyword usage is vital for SEO. This formula helps ensure that you’re staying within your content with keywords, which can result in penalties from search engines.

To accurately assign keyword density I google the main keyword that I am trying to rank to assess the top results and see how much word count they have chosen and how much density are they giving to the keywords. Of course, in our analysis, we also look for how much is the age of the websites that we are trying to beat, and how much topical authority they have, and based on that we come up with a keyword density optimization plan.

4. Click-Through Rate (CTR)

CTR measures the clicks coming on the website based on the impressions that we are receiving. Below is the formula for it.

Formula: CTR = (Clicks / Impressions) * 100

How much should your CTR be on average usually differs from Industry to Industry, however, an agreed-upon range of it is between 1.9-2.5%. This number can change depending on various factors such as trends, the volume of keywords, keywords/content usage on the website, ranking position, brand recognition, and meta tags optimization. 

Generally, SEOs agree that the higher the website ranks on the SERP the higher its CTR going to be. Below is a tabular representation of it.

Ranking Position	Estimated Average CTR
1	| 25% – 30%
2	| 15% – 20%
3	| 10% – 15%
4	| 5% – 10%
5	| 3% – 5%
6-10	| 2% – 4%
11-20	| 1% – 2%
21-30	| 0.5% – 1%

 

But, These are estimated values and can vary on several factors as mentioned above.

5. Conversion Rate

Conversion Rate is calculated by the percentage of visitors coming on the website and completing a transaction or filling out a contact form.

Formula: Conversion Rate = (Conversions / Total Visitors) * 100

A good conversion rate means that the website/app has good content and UI/UX and it is effectively persuading users to complete the intended goals. It’s a key metric for measuring the success of your SEO strategies. To optimize this we generally make sure that the website/app has a checklist of things such as good content and UI/UX, so users can easily navigate to the website and complete the journey. The website loads quickly.

6. Return on Investment (ROI)

ROI measures the profitability of your SEO efforts by comparing the revenue generated to the cost of those efforts. Such as the number of people put on the project based on the income they have is calculated by the revenue/profit the team brings to the project.

Formula: ROI = [(Revenue – Cost of SEO) / Cost of SEO] * 100

or

Formula: ROI = [(Net Profit from SEO) / Cost of SEO] * 100

Understanding the ROI of your SEO campaigns helps justify investments and optimize strategies to maximize profitability.

7. Dwell Time

Dwell Time measures the amount of time a user spends on a webpage after clicking on a search result.

Formula: Dwell Time = (Total Time on Page / Number of Visitors)

A longer dwell time suggests that your content is engaging and valuable to users, potentially boosting your search engine rankings.

8. Pages Per Session

Pages Per Session calculates the average number of pages a visitor views during a single session on your website.

Formula: Pages Per Session = (Total Pages Viewed / Total Sessions)

Higher pages per session indicate that users are exploring your site thoroughly, which can lead to increased engagement and conversions.

9. Cost Per Click (CPC)

CPC is used in pay-per-click (PPC) advertising to measure the cost of each click on an ad.

Formula: CPC = (Total Cost of Clicks / Total Clicks)

Understanding CPC helps manage advertising budgets effectively, ensuring you get the most value from your PPC campaigns.

10. Organic Search Traffic

Organic Search Traffic represents the number of visitors who arrive at your website through organic (non-paid) search engine results.

Organic search traffic is crucial for building a sustainable online presence. It’s typically tracked using website analytics tools.

11. Page Authority and Domain Authority

These metrics, developed by Moz, provide an estimate of a page’s or domain’s ability to rank in search engine results. They are not calculated with a specific formula but are determined based on various factors such as backlinks, content quality, and user engagement.

Page and domain authority are essential for understanding your site’s competitive position in search engine rankings.

12. Breadth of Keyword Ranking

This metric assesses the number of different keywords for which a webpage or website ranks in search engine results. It’s often measured using SEO software.

A broader keyword ranking indicates that your content is relevant and competitive across various search queries.

13. Pageviews

Pageviews measure the total number of pages viewed on your website. It’s a fundamental metric tracked in website analytics.

Analyzing pageviews helps identify which pages are the most popular and which might need optimization.

14. Exit Rate

Exit Rate indicates the percentage of visitors who leave your website after viewing a particular page.

**Formula: Exit Rate = (Number of Exits from a Page / Total Views of the Page

These are some SEO formulas that as an SEO Specialist you should be aware of. If I have missed anything or if you would like to share some insights about these blogs.