This calculator helps you find the appropriate sample size for estimating the proportion of a population that has a particular property within a specified margin of error.
You need to provide the confidence interval, the margin of error, and the sample proportion (%) below and click the ‘Calculate’ button:
Recommended sample size: 385
The confidence interval is usually 90%, 95%, or 99%. If you don’t know the sample proportion, leave it as 50%.
The formula to calculate the sample size is:
n = p*(1-p)*(Zα/2/E)2
n is the sample size,
p is the sample proportion,
Zα/2 is the z critical value, and
E is the margin of error.
I hope this calculator is useful. Happy analyzing!