**SAMPLE SIZE CALCULATOR**

Minimum sample size calculations:

**This application calculates the minimum sample of respondents needed in order to achieve the required level of research accuracy.**

By taking into account an expected percentage, as well as the corresponding confidence interval, it is possible to calculate the sample size needed for a given market research survey.

*For instance*

*Research is needed to evaluate the level of use of Product A among anaesthetists. The desired confidence interval is +/-8. Approximately one third of anaesthetists is expected to be using Product A.*

*How many anaesthetists need to be interviewed in order to achieve this margin of error?*

*At 5% risk level*, for an expected percentage of 33%, with a confidence interval of +/-8, minimum sample size is 133 anesthetists.*

*In other words, if you interview a minimum of 133 anesthetists, there is a 95% chance to get a confidence interval of +/-8 if the proportion of Product A users in the anesthetist sample is 33%.*