Sample Size & Power
Estimate data-collection needs from your precision or effect target and stated planning assumptions.
Plan sample size
- Required observations
- 62
- Target margin
- 5 outcome units
- Approximate achieved margin
- 4.978 outcome units
Precision by sample size
Manual tools are free to use in this session. Saving online requires sign-in and eligible workspace access. Saving and pricing
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How it works
Choose the estimation or two-group comparison objective.
Enter precision or effect size and the requested planning assumptions.
Review sample requirements and the normal-approximation notes.
Saving and pricing
Free in your session
Manual tools and file downloads are free. Downloads stay on your device.
Saving online
Sign in to check workspace access and payer eligibility. Paid storage requires your acceptance of the displayed rate.
$5 per 30 days while projects are kept online, including 1 GB across the workspace. Extra storage is $0.01 per MB per 30 days, prorated by stored size and time.
Optional AI
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All prices are in USD. Storage includes retained versions. MB and GB use decimal units. Published rates do not grant access or enable a purchase. Full pricing details · Check your account
Organization context
Choose the organization for this app’s saved work and AI Q&A. Membership alone does not authorize billing; payer access is checked separately. Nothing is enrolled or charged by this choice.
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