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Sample Size Calculator
Determine the required sample size for your study
Calculation Type
?
Choose whether you are estimating a mean or a proportion.
Estimate a Mean
Estimate a Proportion
Population Std Dev (sigma) or estimate
Estimated Proportion (0 to 1, use 0.5 if unknown)
Margin of Error (E)
Confidence Level
90%
95%
99%
Population Size (optional, for FPC)
?
Leave blank for infinite population. Enter a finite population size to apply Finite Population Correction.
Calculate Sample Size
Results
Critical Value (z)
Required Sample Size (infinite pop)
Finite Pop Correction Applied?
Adjusted Sample Size
Mean:
n = (z*sigma/E)^2
Proportion:
n = z^2*p*(1-p)/E^2
FPC:
n_adj = n0 / (1 + (n0-1)/N)