Sample Size Calculation for Unmatched Case-Control Studies

Version 3.03.17

Two-sided significance level (alpha):
(Usually 0.05)
Power (% chance of detecting):
(Usually 80)
Proportion of controls with exposure:
(Between 0.0 and 1.0)

Ratio of sample size, Controls / Cases:

 (For equal samples, use 1.0)

Please fill in one of the following (leave others as zeros)

Calculated
Proportion of cases with exposure:
(Between 0.0 and 1.0)
Odds ratio  

  Kelsey Fleiss Fleiss with CC
 Sample Size - Cases:

Sample Size - Controls
Total sample size

Note: Kelsey et al., Methods in Observational Epidemiology, 2nd Edition, Table 12-15; and Fleiss, Statistical Methods for Rates and Proportions, formulas 3.18 & 3.19; CC = continuity correction factor.  All calculations are rounded up to the nearest integer.