Digital marketing calculators
A/B Test Sample Size.
Estimate sample size per variant using a two-proportion z-test approximation. Use an absolute or relative minimum detectable effect and keep the assumptions visible.
Browser-based tool
Use A/B sample size
Nothing you enter here is sent to a Website-Me server.
01 / use the tool
How to use A/B sample size
- Enter the values you know in the form.
- Run the tool and review the result alongside the notes below.
02 / interpret the output
What the result means
The approximation estimates the observations needed in each variant to detect the supplied effect at the selected alpha and power.
Important considerations
- This is an approximation, not a substitute for experiment design or sequential-testing decisions.
- The effect must be plausible and the conversion definition stable.
Worked example
Use a small, realistic example first so you can see how the output changes when one input changes.
03 / continue working
Related tools
Move to the next relevant task without losing the context of this page.
04 / relevant support
Need help applying the result?
The tool is a useful starting point. Website-Me can help connect the next step to the wider site, SEO or GEO work.