SUPR-Q is a standardized questionnaire used to measure the quality of a website or digital product’s user experience (UX). It was developed by the Nielsen Norman Group and is based on the ISO 9241-11 standard for usability.

The SUPR-Q questionnaire generates a composite score and a percentile rank, which are calculated using the following formulas:

Composite Score = (Ease of Use + Credibility + Appearance + Satisfaction + Loyalty + Goal Attainment + Effectiveness + Learnability) / 8

Percentile Rank = (Number of websites/products with a lower composite score / Total number of websites/products in the sample) x 100

In these formulas, “Ease of Use”, “Credibility”, “Appearance”, “Satisfaction”, “Loyalty”, “Goal Attainment”, “Effectiveness”, and “Learnability” are the scores from the 8 individual items on the SUPR-Q questionnaire. Respondents rate each item on a scale of 1 to 7, with higher scores indicating a better user experience.

The composite score is the average of the 8 item scores, which ranges from 1 to 7. This score is used to give an overall rating of the website or digital product’s user experience.

The percentile rank is used to compare the composite score to a sample of similar websites or digital products. It ranges from 0 to 100, with 100 being the best possible score. A percentile rank of 75, for example, would indicate that the website or product has a better user experience than 75% of the websites or products in the sample.

It’s important to note that the SUPR-Q questionnaire is designed to be used as a benchmarking tool, and it should be used in conjunction with other UX research methods, such as user testing, to get a comprehensive understanding of the user experience.