Sorry, this calculator requires JavaScript be enabled in your browser to function.
How sure do you need to be?
Somewhat sure (90%)
Pretty sure (95%)
Very sure (99%)
Expected response rate (click-through rate, action rate, etc.)
%
Ex: 3.2
How much of a difference do you expect this test to make?
Large amount (25%)
Medium amount (15%)
Small amount (5%)
Find my sample size!