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5 Essential Usability Metrics in UX Research

 By Userlytics
 Feb 06, 2024
Home  »  Blog   »   5 Essential Usability Metrics in UX Research

Ever launched a new feature, expecting fireworks but got crickets instead? You’re not alone. That gap between what we think users want and what they actually do is where usability metrics come to the rescue. Like a trusty GPS for navigating the user experience wilderness, these usability metrics guide us from the land of guesswork to the haven of user satisfaction.

In this article, we unpack the five most important usability metrics that’ll show you whether your product is a hit or a miss.

What are Usability Metrics?

Usability metrics are the superheroes in the world of UX design and UX research, providing a treasure trove of quantitative insights into user-product interactions. These usability metrics form the backbone of user experience research, turning the spotlight on everything from task completion rates to user satisfaction.

With usability metrics in your toolkit, you’re equipped to unearth vital insights that steer your product development in the right direction. Essentially, usability metrics are your secret weapon to crafting products that truly vibe with your users, ensuring every level of interaction is nothing short of remarkable.

The Different Types of Usability Metrics

To understand how usability metrics can be measured and evaluated, we need to understand what their purpose is. We’ll introduce the 5 most important usability metrics: Usability, User Satisfaction, Engagement, Conversion Rate, and Retention Rate.


Usability is the bedrock of UX research, focusing on how effectively, efficiently, and satisfactorily a user can interact with a product. The overall usability score is determined by focusing on three key metrics:

Task Success Rate

Example: Consider an e-commerce platform where you want to evaluate the effectiveness of the checkout process.

How to Calculate the Task Success Rate: (Number of Successful Checkouts / Total Checkout Attempts) x 100. This usability metric is a direct indicator of how intuitively users can navigate through the buying process.

Error Rate

Example: Users frequently misinterpret a ‘save for later’ button for ‘add to cart’.

How to Calculate the Error Rate: (Total Number of Misinterpretations / Total Number of Attempts) x 100. This usability metric pinpoints where the product’s design might be causing confusion.

Time on Task

Example: The average duration users spend finding a product using the search function.

How to Calculate the Time on Task: Total Search Time / Number of Searches.

User Satisfaction

User satisfaction reflects how users feel about your product. This metric encompasses various aspects of the emotional and psychological responses elicited by the user experience. Tools such as the System Usability Scale (SUS), Net Promoter Score (NPS), and Customer Satisfaction Score (CSAT) are instrumental in capturing user satisfaction. These usability metrics act like feedback megaphones, amplifying the voice of the user to give you a crystal-clear snapshot of their satisfaction.  Let’s unpack each one of these usability metrics.

The System Usability Scale (SUS)

How to Calculate the System Usability Scale (SUS): The SUS score is derived from a standardized 10-question survey, providing a global view of subjective usability metrics. Participants are asked to express their level of agreement or disagreement with various statements about systems, websites, apps, or prototypes, using prompts like “Please indicate how much you agree or disagree.”

Net Promoter Score (NPS)

Example: Post-interaction, users indicate their likelihood of recommending your service.

How to Calculate the Net Promoter Score (NPS): % Promoters (users who score 9-10, showing they’re highly likely to recommend the service) – % Detractors (users who give a score of 0-6, indicating they’re unlikely to recommend). This usability metric offers insights into user loyalty and satisfaction.

 Customer Satisfaction Score (CSAT)

Example: Users rate their satisfaction with a feature update.

How to Calculate the Customer Satisfaction Score (CSAT): (Sum of Satisfaction Scores / Number of Responses) x 100. This usability metric gauges immediate user reactions to specific product elements.


Engagement is one of the most important usability metrics. It offers insights into how well users interact with your product. Its key indicators include Session Length, Frequency of Use, and Page Views/Interaction Rates. Let’s go over each one of these.

Session Length

Example: The time users spend per session on a new app feature.

How to Calculate the Session Length: Total Time on Feature / Number of Sessions. This usability metric helps understand how engaging the new feature is.

Frequency of Use

Example: How often users return to the app within a given week.

How to Calculate the Frequency of Use: Total App Opens / Number of Users. A key usability metric for measuring app stickiness.

Page Views/Interaction Rates

Example: The number of pages a user views in one session.

How to Calculate Page Views/Interaction Rates: Total Page Views / Number of Sessions. This usability metric helps identify which content is most engaging or if there are navigation issues.

Conversion Rate

Conversion rate is pivotal in contexts where a specific user action is desired, such as making a purchase or signing up for a service. This usability metric measures the percentage of users who take a desired action, providing insights into the design’s effectiveness in facilitating user goals. Optimizing the conversion rate is often a primary objective for product marketers and UX designers alike, as it directly correlates with the product’s success. Let’s go over an example and how to calculate this usability metric.

Example: The rate at which visitors to your landing page sign up for a newsletter.

How to Calculate the Conversion Rate: (Number of Sign-Ups / Number of Visitors) x 100. This is an essential usability metric for evaluating the effectiveness of call-to-action elements.

Read: How Userlytics and Blakcbaud collaborated to increase the Conversion Rate of their demo booking form.

Retention Rate

Retention rate is a crucial usability metric for understanding how many users continue to use a product over time. It is especially important for services that rely on prolonged user engagement, such as subscription-based platforms. A high retention rate suggests that users find continued value in the product, highlighting its long-term viability.

Example: The percentage of users who continue to use the app after their first month.

How to Calculate the Retention Rate: (Number of Users at End of Month / Number of New Users) x 100. This usability metric is crucial for assessing long-term user satisfaction and product loyalty.

Download our Whitepaper: How A Positive User Experience Can Ensure Customer Retention And Upsell Within Subscription Businesses

Why is it Important to Measure Usability Metrics?

Incorporating usability metrics into your development cycle is not merely a best practice—it’s a necessity for creating great products. These usability metrics (Usability, User Satisfaction, Engagement, Conversion Rate, and Retention Rate)  provide objective data that can confirm or challenge your assumptions, allowing you to iterate with confidence. Usability metrics together form the foundation of a strategy that prioritizes user needs, leading to higher satisfaction, increased engagement, and ultimately, business success.

Get a 360° view of your User Experience with the ULX ® Benchmarking Score

But here’s the twist: usability metrics are just the tip of the iceberg. Imagine your app or website is very user-friendly (high on usability metrics) but fails to draw users in (low appeal) – not quite the win you hoped for, right? Or it’s engaging but doesn’t pop up in people’s minds when they need your product or service. 

The UX Consulting team of Userlytics came up with the ULX® Benchmarking Score, which gives you a 360°, all-angles view of user experience. It goes beyond mere usability metrics by evaluating 18 attributes spread across 8 key areas, something most tools miss.

This holistic user experience metric has been fine-tuned through rigorous statistical analysis, thanks to our massive user testing panel of over two million participants and extensive UX testing. It gives you the power to benchmark your products over time, against competitors, and across different versions.

It hands you three vital pieces of information: a comprehensive overall score, detailed scores for each of the 8 categories like Usability, Trust, and Appeal, and individual scores for the 18 key attributes, offering a crystal-clear snapshot of your product’s performance. This exclusive diagnostic solution, only available through Userlytics, is your ticket to mastering UX.


The strategic application of usability metrics is indispensable in creating outstanding digital products. They enable you to translate user behaviors and preferences into actionable insights, driving the design of intuitive and enjoyable user experiences. By committing to a rigorous analysis of usability metrics, you guarantee that every design decision is informed, and you can ensure your products not only meet but exceed user expectations.

The usability metrics discussed in this article are seamlessly integrated into the Userlytics platform, allowing you to easily set them up and track them on your own. Why not schedule a free demo or have a conversation with our team to learn more?

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