Just keep in mind that sample size and margin of error are related: the larger margin of error you pick, the smaller sample size you’ll need. Calculating sample size with PythonThere are a couple ways to run a quick calculation. Putting in our numbers there, we get:2,345 as the sample size. ##Post-script on the Power of a TestSomething you might often come across while reading up on picking the right sample size is “power of test.” (This can be performed once)[https://en.wikipedia.org/wiki/Statistical_power] you actually have your sample size. What you’re really testing for is whether the sample size you’re taking matches the population.