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Sample Size Calculator
This calculator can be used to determine the minimum number of people that need to be interviewed in order to obtain results that reflect the target population to an acceptable level of accuracy.
How To Interpret The Results
For example, suppose you wish to carry out a survey to determine the percentage of respondents who would be likely to take up a new product offering. The target population from which you can randomly select your sample is known as 1,000. You wish to test your results at the 95% confidence level and you are prepared to accept a margin of error of ±5%.
The number of people that need to be interviewed is 278.
Enter The Margin Of Error That Is Acceptable (+/-%)
Enter Population Size (If Unknown Use 20,000)
Select Desired Confidence Level (%)
80
85
90
95
99
99.5
99.9