Free Calculator
MaxDiff Sample Size Calculator
Calculate the minimum sample size for MaxDiff (Best-Worst Scaling) studies based on the number of items, set size, and tasks.
Study Design Parameters
How many features, messages, or concepts in your MaxDiff study (typically 10–30)
How many items appear in each best-worst choice task (typically 4–5)
Number of best-worst sets each respondent completes (typically 8–15)
⚠️ Each item appears only 2.7× per respondent. At least 3 appearances are needed for stable estimates. Increase tasks or reduce items.
Minimum Sample
188
Statistical floor
Recommended Sample
226
With design buffer
With Recruitment Buffer
260
+15% for dropouts
Item appearances per respondent
With this design, each item appears 2.7× per respondent. Increase tasks to improve stability.
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