Sample Size for a Proportion
How many respondents do you need for a given margin of error?
385
Recommended n
About this tool
Computes n = z²·p·(1−p)/m². Pick your margin and confidence; defaults to p=0.5 (worst case) and 95% confidence.
How many respondents do you need for a given margin of error?
Computes n = z²·p·(1−p)/m². Pick your margin and confidence; defaults to p=0.5 (worst case) and 95% confidence.