Sample size (proportion)
ClientSimple random sample size for margin e.
n ≈ z²pq/e² for proportion estimates.
About Sample size (proportion)
n ≈ z²pq/e² for proportion estimates. The interactive transform on this page runs in your browser tab—Toolcore does not need your paste for the core operation described above.
How to use this page
Paste or type in the main workspace, run the primary action from the toolbar, then copy or download the result. Use Load example when the page offers it, or URL prefill (?q= / ?qb=) so agents and tickets open the same input.
Common use cases
- Sample size (proportion) for quick local checks without uploading data.
- Copy results into tickets, docs, or classroom notes.
Common mistakes to avoid
Unexpected input shape
See the intro and how-to notes for accepted formats.
FAQ
Is processing local?
Yes—this runs entirely in your browser.
Agent prefill?
Open the page directly—multi-field inputs are not URL-prefilled.
More tools
Related utilities you can open in another tab—mostly client-side.
Confidence interval (mean)
Clientmean ± z·σ/√n from comma-separated sample.
Z-test proportion
Clientz = (p̂ − p₀)/√(p₀(1−p₀)/n)—enter successes,n,p0.
Math expression evaluator
ClientEvaluate basic + − × ÷ arithmetic with parentheses in your browser—no variables.
Percentage calculator
ClientPercent of a value, ratio to percent, and percent change—no server round-trip.