The calculator found below will compute the sample size given the population size, estimated population percentage, margin of error and confidence level.
If the population percentage cannot be estimated, then the Simple Sample Size Calculator should be used instead.
You may use this calculator to determine, out of a group (whose number is the population size) of people, how many should be surveyed to accurately determine the percentage who would choose a particular answer for a survey question. Since it is usually not possible to survey everyone in the entire group, only some (the sample size) are interviewed. If the sample group truly represents the whole population, then the sample percentage (which can be
measured) will be no further from the actual population percentage (which is unknown) than the margin of error, with a certain confidence level.
To use this calculator, enter numbers into the boxes above the Calculate button, then click on the Calculate button to see the result underneath.
Further information about the calculations within this calculator may be found at sample size calculations.