UX research calculators
The statistics that come up in almost every usability study or thesis: how many participants to recruit, whether design B really beat design A, and how to report completion rates, task times and reliability properly.
Each tool follows the methods in Sauro and Lewis’s Quantifying the User Experience and gives you a sentence you can paste into a report.
Sample size calculator
How many participants you need for a precise score, an A/B comparison or problem discovery.
A/B test calculator
Compare two designs with a t-test or a two-proportion test, with confidence intervals and effect size.
Completion rate calculator
Adjusted-Wald confidence interval and best estimate for small-sample task success rates.
Time on task calculator
Geometric mean, confidence interval and median for skewed task times.
Cronbach’s alpha calculator
Internal consistency for questionnaire data, with item–total correlations and alpha if deleted.
Scoring a questionnaire instead? Go to the questionnaire calculators.