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Most experimentation tools were designed for statisticians, not for the fast-moving growth and product teams inside startups. They’re complex, full of jargon, and often leave teams unsure whether they can trust their results.
That’s exactly the problem Simon Jackson, who led experimentation at Meta, Canva, and Booking.com, set out to solve.
Now working as an independent consultant, Simon has launched The Experimenter’s Calculator—a free, startup-friendly suite of calculators designed to make reliable experimentation accessible to everyone, not just big tech.
Why this matters
In many startups and scaleups, experiments fail not because teams don’t test, but because the tests don’t teach them anything. The common pitfalls:
- Too few users to reach significance.
- Inconclusive results.
- No clear next steps.
The Experimenter’s Calculator helps teams avoid these traps by designing experiments properly from the start—so results are reliable, actionable, and worth the effort.
What it offers
The Experimenter’s Calculator includes four lightweight, practical tools:
- Sample Size Calculator → Find out how many users you need to trust your results.
- Test Duration Calculator → Know how long you should run your test.
- Effect Detection Calculator → Understand the smallest effect you can measure.
- Test Results Analyzer → Analyze experiments you’ve already run.
Each tool is designed to be fast, simple, and intuitive—no stats degree required.
How it works
- Visit calculator.drsimonj.com.
- Pick the calculator you need.
- Enter your baseline data (like conversion rate) and instantly see results.
✨ Pro tip: Log in to save defaults so the calculators always work the way you want.
See a quick walkthrough here: Demo video.
About Simon Jackson
With years of experience building experimentation cultures at Meta, Canva, and Booking.com, Simon knows what it takes to design tests that actually move the needle. Today, he helps APAC businesses scale high-impact experimentation—and The Experimenter’s Calculator is his way of making those same practices available to any team.
