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Duration Estimator

Estimate how long your experiment needs to run

Quick Start: Try a Scenario

Experiment Parameters

Configure your traffic and test settings

Average daily visitors to your experiment

5.0 %

Your current conversion rate

+5.0 %

Drag to see how MDE affects runtime

What-if: Smaller MDEs require more traffic and longer runtimes. Use the slider to find the sweet spot between sensitivity and practicality.

Power
Selected: 80
Estimated Runtime Acceptable
3 weeks, 4 days

A bit long, but still practical for most teams.

Sample per Variant

122.1K

Total Sample

244.2K

Runtime by MDE

See how different effect sizes affect your experiment duration

+1%
85 weeks, 5 days
+3%
9 weeks, 5 days
+5%
3 weeks, 4 days
+10%
1 week
+20%
2 days

Summary

Daily traffic 10,000
Baseline rate 5.0%
MDE +5.0% relative
Expected variant rate 5.25%
Power / Confidence 80% / 95%

These tools are built with care, but we can't guarantee accuracy for every scenario. If something seems off, please reach out at [email protected] — we'd love to hear from you. We hope these tools help you run better experiments!