Confidence Interval Calculator – Proportion
Compute a confidence interval using the Proportion method. Enter sample stats; we apply the correct formula. For planning only.
Basic statistics
Enter numbers to compute.
How it works
We apply Proportion formula (z or t, proportion or mean) to your sample data. Result is an interval estimate.
When to use it
Use when reporting survey or experiment results with Proportion.
Frequently asked questions
When use z vs t?
Use z for known population SD or large n; t for small samples.
Is this for proportions?
We offer both proportion and mean methods.