AB Test Duration Calculator and Sample Size

Use this AB test duration calculator to estimate the sample size and the duration  your test would need to run for based on your current conversion rate, what lift you expect, the number of variations you will be running and the average daily traffic your site gets. Using this duration calculator will assist you in avoiding  false positives and help to maximise the validity of your A/B testing program.

There are 4 pieces of information required for the calculator to provide the estimates, these are:

  1. Your current conversion rate for the default page
  2. What % lift you want to achieve (smaller lifts take longer – try the calculator and you will see the effect)
  3. How many different variations of the original page you want to include in the test (more variations = more traffic required)
  4. Your average daily traffic based on your analytics

AB Test Duration Calculator

Existing conversion rate (%)
Minimum improvement you would like to see (%)
Number of variations (including control)
Average daily visitor numbers
To achieve statistically significant results* the test would need a run time of 27 days and would be viewed by 27022 visitors.
* Using a 95% confidence level

Check out out Return on Investment Calculator here

Kraken Data is software agnostic, we work with your A/B testing software of choice. Amoungst the ones we support and recommend are:


Adobe Target



If you would like to discuss your optimisation or analytics programs, please contact us.