Enhance Your Website Experience with the System Usability Scale (SUS)
Sep 14, 2025
What & Why is SUS?
Developed by John Brooke in 1986, SUS is a simple 10-item questionnaire designed to assess a product's usability. It provides a score ranging from 0 to 100, which helps teams understand how users perceive their system's usability.
Why use SUS?
Quick & Easy | Standardised | Versatile |
|---|---|---|
Takes only a few minutes to complete and analyse. | Provides a reliable benchmark across different systems. | Suitable for websites, apps, software, and even physical products. |
Interpreting SUS Score
A score below 50 suggests poor usability.
Scores between 50-70 indicate average usability.
Above 70? You’re doing great, but there's always room to improve!
Pair scores with adjectives like "Poor," "OK," or "Excellent" for context.
SUS Survey Questions
10 example questions you can use in the SUS survey
I think I would like to use this website frequently.
I found this website unnecessarily complex.
I thought the website was easy to use.
I think I would need the support of a technical person to use this website.
I found the various functions on this website to be well-integrated.
I thought there was too much inconsistency on this website.
I would imagine that most people would learn to use this website very quickly.
I found the website very cumbersome to use.
I felt very confident using this website.
I needed to learn a lot of things before I could start using this website.
Key Topics to Explore
Steps to Conduct a SUS Survey
Select participants after they’ve interacted with the system.
Administer the 10-item questionnaire immediately after the session.
Steps to Conduct a SUS Survey
Scoring SUS in Detail
Odd-numbered items contribute positively; even-numbered items are reverse-scored.
Multiply the final sum by 2.5 for a score out of 100.
SUS Beyond Scores
Combine with task success rates, time-on-task, or error rates for richer insights.
Map scores to qualitative adjectives (e.g., "Good" or "Poor").
SUS for Non-Traditional Products
Adapt it for physical products or unconventional interfaces like voice assistants.
Tips for Maximising SUS Effectiveness
Ensure clear instructions to participants.
Use SUS results to spark discussions in your team about improvements.
Limitations of SUS
While SUS is a powerful tool, it’s not without its limitations:
Lack of Diagnostic Depth | Subjectivity | Interpretation |
|---|---|---|
It tells you there’s a problem, but not what or where it is. | Scores depend on user perceptions and experience levels. | Requires careful contextual analysis to avoid overgeneralising results. |
Applications of SUS
SUS is widely used across various domains, such as
Software & Web Development | Hardware Usability | Healthcare |
|---|---|---|
Evaluate user-friendly designs for websites, apps, and platforms. | Test interfaces for devices like ATMs, kiosks, or consumer electronics | Evaluate AR/VR systems, voice assistants, and IoT devices. |
Real-World Success Stories
Google Leveraged SUS for interface designs across products.Cell 1-1 | Healthcare Systems improved user interaction with medical records software. | Consumer Electronics: Enhanced usability in smart home devices and wearables. |
When to Use SUS
From startups to Fortune 500 companies, SUS has been used to evaluate
Early Prototypes | Usability Testing | Post-Release |
|---|---|---|
Get a usability snapshot to refine the product. | After task completion during testing sessions. | Gather user feedback for ongoing improvements. |
Benefits of SUS
From startups to Fortune 500 companies, SUS has been used to evaluate:
Efficient | Reliable | Universal |
|---|---|---|
Minimal effort with quick results. | Standardised and widely recognised. | Works across diverse domains, from software to physical products. |
Enhancing SUS with Other Methods
To address its limitations, pair SUS with
Task Success Rates | Time-on-Task Analysis | Error Analysis |
|---|---|---|
See how many users complete tasks successfully. | Understand efficiency alongside usability. | Highlight specific interaction breakdowns. |
Customising SUS
While the original SUS is robust, slight adaptations can make it even more relevant
Non-Digital Products | Localised Contexts | Focus Areas |
|---|---|---|
Modify statements for physical products. | Translate and adapt phrasing for cultural nuances | Tailor questions to specific user goals or experiences. |
Future Trends in SUS
While the original SUS is robust, slight adaptations can make it even more relevant
AI-Driven Analysis | Integration with Advanced Metrics | Adapting to Emerging Tech |
|---|---|---|
Automating scoring and contextual insights | Pairing SUS with eye-tracking, sentiment analysis, or behavioural data. | Expanding usability evaluation for AI, machine learning systems, and immersive technologies. |
What & Why is SUS?
Developed by John Brooke in 1986, SUS is a simple 10-item questionnaire designed to assess a product's usability. It provides a score ranging from 0 to 100, which helps teams understand how users perceive their system's usability.
Why use SUS?
Quick & Easy | Standardised | Versatile |
|---|---|---|
Takes only a few minutes to complete and analyse. | Provides a reliable benchmark across different systems. | Suitable for websites, apps, software, and even physical products. |
Interpreting SUS Score
A score below 50 suggests poor usability.
Scores between 50-70 indicate average usability.
Above 70? You’re doing great, but there's always room to improve!
Pair scores with adjectives like "Poor," "OK," or "Excellent" for context.
SUS Survey Questions
10 example questions you can use in the SUS survey
I think I would like to use this website frequently.
I found this website unnecessarily complex.
I thought the website was easy to use.
I think I would need the support of a technical person to use this website.
I found the various functions on this website to be well-integrated.
I thought there was too much inconsistency on this website.
I would imagine that most people would learn to use this website very quickly.
I found the website very cumbersome to use.
I felt very confident using this website.
I needed to learn a lot of things before I could start using this website.
Key Topics to Explore
Steps to Conduct a SUS Survey
Select participants after they’ve interacted with the system.
Administer the 10-item questionnaire immediately after the session.
Steps to Conduct a SUS Survey
Scoring SUS in Detail
Odd-numbered items contribute positively; even-numbered items are reverse-scored.
Multiply the final sum by 2.5 for a score out of 100.
SUS Beyond Scores
Combine with task success rates, time-on-task, or error rates for richer insights.
Map scores to qualitative adjectives (e.g., "Good" or "Poor").
SUS for Non-Traditional Products
Adapt it for physical products or unconventional interfaces like voice assistants.
Tips for Maximising SUS Effectiveness
Ensure clear instructions to participants.
Use SUS results to spark discussions in your team about improvements.
Limitations of SUS
While SUS is a powerful tool, it’s not without its limitations:
Lack of Diagnostic Depth | Subjectivity | Interpretation |
|---|---|---|
It tells you there’s a problem, but not what or where it is. | Scores depend on user perceptions and experience levels. | Requires careful contextual analysis to avoid overgeneralising results. |
Applications of SUS
SUS is widely used across various domains, such as
Software & Web Development | Hardware Usability | Healthcare |
|---|---|---|
Evaluate user-friendly designs for websites, apps, and platforms. | Test interfaces for devices like ATMs, kiosks, or consumer electronics | Evaluate AR/VR systems, voice assistants, and IoT devices. |
Real-World Success Stories
Google Leveraged SUS for interface designs across products.Cell 1-1 | Healthcare Systems improved user interaction with medical records software. | Consumer Electronics: Enhanced usability in smart home devices and wearables. |
When to Use SUS
From startups to Fortune 500 companies, SUS has been used to evaluate
Early Prototypes | Usability Testing | Post-Release |
|---|---|---|
Get a usability snapshot to refine the product. | After task completion during testing sessions. | Gather user feedback for ongoing improvements. |
Benefits of SUS
From startups to Fortune 500 companies, SUS has been used to evaluate:
Efficient | Reliable | Universal |
|---|---|---|
Minimal effort with quick results. | Standardised and widely recognised. | Works across diverse domains, from software to physical products. |
Enhancing SUS with Other Methods
To address its limitations, pair SUS with
Task Success Rates | Time-on-Task Analysis | Error Analysis |
|---|---|---|
See how many users complete tasks successfully. | Understand efficiency alongside usability. | Highlight specific interaction breakdowns. |
Customising SUS
While the original SUS is robust, slight adaptations can make it even more relevant
Non-Digital Products | Localised Contexts | Focus Areas |
|---|---|---|
Modify statements for physical products. | Translate and adapt phrasing for cultural nuances | Tailor questions to specific user goals or experiences. |
Future Trends in SUS
While the original SUS is robust, slight adaptations can make it even more relevant
AI-Driven Analysis | Integration with Advanced Metrics | Adapting to Emerging Tech |
|---|---|---|
Automating scoring and contextual insights | Pairing SUS with eye-tracking, sentiment analysis, or behavioural data. | Expanding usability evaluation for AI, machine learning systems, and immersive technologies. |