Free Tools
Calculators

A/B Test Duration Calculator

Turn required sample size into a run-time estimate using daily traffic and number of variants.

Run tests in Otter

Estimated duration

24 days

based on 23,646 total visitors

Per variant target

7,882

visitors before calling the test

Related tools

Sample Size Calculator

Find the visitors needed per variant before an experiment can detect the lift you care about.

Significance Calculator

Check completed control and variant counts with a two-sample conversion-rate test.