These online calculators allow you to evaluate the sample size required to obtain an expected set of results, where a one-sided confidence interval or hypothesis test for a binomial proportion is of interest. The calculators were developed for the 2019 paper "How many to sample? Statistical guidelines for monitoring animal welfare studies." which Darryl coauthored. See the paper for details of the underlying calculations.

The user is required to specify input values below, and the results are updated automatically. Note that depending on the speed of your internet connection, there may be a lag in the updating.

As in any prospective sample size calculation, the below below is an indication of the expected results that would be obtained given the input values. The actual results are likely to be different due to a range of factors, including natural variability and randomness, true values being different to input values, etc.

Collecting the right type and right amount of data is key to the success of any study. Helping people with their study design is one of the more satisfying aspects of our business. Contact us to discuss your needs.