Statistical Calculators forA/B Testing
Free tools for every stage of your experimentation workflow.No signup required. All calculations run in your browser.
Why You Need A/B Testing Calculators
Running a reliable A/B test takes more than picking a winner. You need to size your experiment correctly before launch, catch data quality issues while it runs, and apply the right statistical methods when it ends. These free statistical calculators cover every step of the experimentation workflow so you can make confident, data-backed decisions.
Plan
Calculate sample size, test duration, and minimum detectable effect before you start.
Monitor
Check for sample ratio mismatch and validate data normality while your test runs.
Analyze
Measure statistical significance, run Bayesian analysis, and calculate experiment ROI.
All Calculators
From experiment planning to results analysis, everything you need in one place.
Built for Practitioners
No fluff. Just the tools you need to make data-driven decisions with confidence.
Instant Results
All calculations run in your browser with zero latency.
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Proven Formulas
Industry-standard statistical methods used by professionals.
Completely Free
No limits, no credit card, no catches. Free forever.
The A/B Testing Workflow
Our calculators cover every phase of running a successful experiment.
Plan Your Experiment
- Calculate required sample size
- Estimate test duration
- Determine minimum detectable effect
- Analyze historical variance
Monitor Data Quality
- Check for sample ratio mismatch
- Validate data normality
- Verify traffic allocation
- Detect issues before they compound
Analyze Results
- Calculate statistical significance
- Get confidence intervals
- Run Bayesian analysis
- Calculate experiment ROI
Frequently Asked Questions
Common questions about A/B testing statistics and our calculators.
Related Resources
Learn when a result actually matters.
Test whether a variant is not worse.
100+ experimentation terms explained.
Essential reading on experimentation.
Structured learning paths for experimentation.
Compare experimentation platforms.
Ready to Analyze Your Test?
Get started with our free statistical calculators and make confident, data-driven decisions.