This calculator determines the sample size for a population proportion from confidence level and desired margin of error.

Sample Size Calculator for a Mean

- First, input the confidence level and desired margin of error.
- Input the expected proportion. Leave it as 0.5 if it's unknown.
- Press the 'Calculate' button to obtain the sample size result.

The following formula is used to calculate the sample size required for a population proportion.

Sample Size (s) = p × (1-p) × (Z_{α/2} / E)^{2}

Where,

p = Expected proportion,

Z_{α/2} = Z-value associated with the confidence level,

E = Desired margin of error.