Point Estimate Calculator
Estimate a population proportion from your sample data, along with a confidence interval around that estimate.
What a point estimate is
A point estimate is a single best guess at a population value, based on sample data. For a proportion (like the share of a population with a certain trait), the point estimate is simply the number of successes divided by the sample size.
How this calculator works
Enter the number of successes observed and your total sample size. The calculator computes the sample proportion as your point estimate, then builds a confidence interval around it using the standard error of a proportion and the critical z-value for your chosen confidence level (90%, 95%, or 99%).
Wider confidence intervals reflect more uncertainty, which shrinks as your sample size grows. This calculator uses the normal (Wald) approximation, which works best when the sample size is reasonably large and the proportion isn’t extremely close to 0 or 1. Provided for general educational and planning purposes.