System Usability Scale
SUSA 10-item questionnaire giving a global view of subjective usability. Alternates positively- and negatively-worded items. Produces a single 0–100 score; 68 is commonly cited as the average.
Ready-to-cite methods sentence
Reliability & validation
Response anchors
Strongly disagree · Disagree · Neither agree nor disagree · Agree · Strongly agree
Known limitations
SUS produces a 0–100 score, not a percentage or percentile. Historically © Digital Equipment Corporation (1986); permissible for research use but commercial licensing varies. Substitute "system" with the product name when administering.
Original citation
Brooke, J. (1996). SUS: A "quick and dirty" usability scale., 189-194.
Questions researchers ask
What does the SUS measure?
A 10-item questionnaire giving a global view of subjective usability. Alternates positively- and negatively-worded items. Produces a single 0–100 score; 68 is commonly cited as the average.
How many items does the SUS have?
The System Usability Scale (SUS) has 10 items.
Is the SUS free to use?
The SUS is free to use for non-commercial academic research. You don't need to pay a license fee, but you should always cite the original publication.
Is the SUS reliable?
Validation studies report Cronbach's α of 0.91. See the reliability section for the population studied and full statistics.
Who developed the SUS, and how do I cite it?
Brooke, J. (1996). SUS: A "quick and dirty" usability scale., 189-194.
Use SUS in Folio Surveyor
Add it to a study with the full items, scoring, and analysis built in.
Related scales
Library entry verified January 2024. Metadata is provided for reference; item wording is available inside Folio Surveyor, subject to each instrument's licensing.