System Usability Scale (SUS) template and scoring guide
How usable is this, really?
The System Usability Scale is a 10-question survey that gives a single usability score from 0 to 100. John Brooke created it in 1986, and it is still used because the questions never change, which means you can compare your score with other products and with your own earlier releases. Below are the questions as they appear in the Great Question template, the scoring method, and how to read the result.
Questions it can answer
- How usable is the product or service?
- How efficient is the product or service?
- How effective is the product or service?
What is the System Usability Scale (SUS)?
The System Usability Scale (SUS) was developed in 1986, that’s 5 years before the first website went live! This tried and tested method has been used to evaluate the usability of products and services for more than 35 years and remains a proven and dependable method. It remains popular due to its simple nature, 10 fixed usability questions and decades of data to determine what a good score is.
Related guide: SUS works best after task-based testing. See our usability testing guide.
Do it faster with a Claude skill: Survey designer. Builds a first draft of this study in Claude that you can edit before you send it.
The questions in this template
These are the questions in the Great Question System Usability Scale template.
These are John Brooke's standard 10 items, in the standard order.
All 10 questions use the same answer type: Linear Scale 1 to 5: 1 Strongly disagree, 5 Strongly agree
I think that I would like to use this system frequently.
I found the system unnecessarily complex.
I thought the system was easy to use.
I think that I would need the support of a technical person to be able to use this system.
I found the various functions in this system were well integrated.
I thought there was too much inconsistency in this system.
I would imagine that most people would learn to use this system very quickly.
I found the system very cumbersome to use.
I felt very confident using the system.
I needed to learn a lot of things before I could get going with this system.
How to run it
When to send. Give SUS right after participants have used the product, either at the end of a usability test session or after a set of real tasks, and before any discussion that might sway their answers. Ask participants to respond with their first reaction and to answer every item. Brooke's original guidance is that if someone cannot answer an item, they should mark the centre point.
Don't edit the items. Keep all 10 statements, their order, and the alternating positive and negative wording. Removing or rewording items means your score is no longer comparable with published benchmarks. Replacing "system" with your product's name or "this website" is common and does not change the scoring. If you want a follow-up about what made the product hard to use, ask it after the 10 items and keep it out of the score.
How to score it. Each item is answered on the template's 5-point scale, from 1 (Strongly disagree) to 5 (Strongly agree).
- For odd-numbered items (1, 3, 5, 7, 9), subtract 1 from the answer.
- For even-numbered items (2, 4, 6, 8, 10), subtract the answer from 5.
- Add the 10 converted values. The total is between 0 and 40.
- Multiply the total by 2.5. The result is the SUS score, from 0 to 100.
Worked example: answers of 4, 2, 4, 1, 4, 2, 5, 2, 4, 2 convert to 3, 3, 3, 4, 3, 3, 4, 3, 3, 3. The total is 32, and 32 × 2.5 = 80.
Calculate a score for each participant, then report the mean across participants.
How to read it. A SUS score is not a percentage. Jeff Sauro's analysis of SUS results from 500 studies at MeasuringU puts the average score at 68, so a score above 68 is above average and below 68 is below average. Report the mean with a confidence interval, and compare it with your own earlier score for the same product as well as with the benchmark.
Sample size. Because SUS is a fixed, well-tested questionnaire, it is commonly run with the same small groups used for usability testing. With small samples, report the confidence interval so readers can see how much the score could move. Comparing two designs or two releases needs more participants than describing one.
What SUS will not tell you. It tells you how usable people found the product, not what to fix. Pair it with task observation or an open question to find the causes.
Advantages
- Easy to compare results with industry standards as the method has been in use for more than 35 years
- Proven and dependable survey for collecting users opinions on the usability of a product
- Quick and easy to execute and analyze the results
Limitations
- Doesn’t evaluate user behavior, instead focuses on the users opinion of the product usability
- No opportunity to explore the reason behind the score participants give for each question
- The questionnaire is administered after the experience, rather than capturing feedback during use
Frequently asked questions
How do you calculate a SUS score?
Subtract 1 from each odd-numbered answer, subtract each even-numbered answer from 5, add the 10 results and multiply by 2.5. That gives a score from 0 to 100 for each participant. Average the participants' scores for the product's score.
What is a good SUS score?
The commonly cited average is 68, from Jeff Sauro's analysis of 500 studies at MeasuringU. Above 68 is above average. A SUS score is not a percentage, so 68 does not mean "68% usable".
Can I change the wording of the SUS questions?
Replacing "system" with your product's name or "website" is common and accepted. Changing the statements themselves, dropping items or changing the scale breaks comparison with the benchmark, so avoid it.
How many participants do I need for SUS?
You can run it with the same small groups you use for usability testing, as long as you report the confidence interval. Comparing two versions, or tracking a change over time, needs more responses than a single read.
Is the System Usability Scale free to use?
John Brooke made SUS freely available with acknowledgement of the source. Cite Brooke's 1996 chapter "SUS: a quick and dirty usability scale" when you report it.