Score the System Usability Scale (SUS) from 10 Likert responses. Returns the standard 0–100 score, the percentile against the industry benchmark of 68, and an adjective grade. Save each participant to compute an average across your sample.
For each statement, click the respondent's score: 1 = Strongly disagree → 5 = Strongly agree.
SUS, developed by John Brooke in 1986, is the most-used usability questionnaire in UX research. It has 10 Likert items, alternating positive and negative tone to reduce response bias. Scoring is standard: subtract 1 from odd-numbered items, subtract the response from 5 for even-numbered items, sum, multiply by 2.5. The result is 0–100 (not a percentage).
Industry benchmark research (Sauro, 2011) shows the average SUS score across hundreds of studies is 68. A score above 68 indicates above-average usability; above 80 is "excellent"; below 51 is "poor". The percentile shown here maps your score to this benchmark distribution.
Collect at least 10–12 participants per condition to produce a reliable estimate. SUS is best used comparatively (your version against a competitor, or redesign against original) rather than as an absolute measure.
Related: NPS calculator, task success calculator, usability testing guide, UX method finder.