Confidence Interval Calculator

Calculate the confidence interval for a population mean.

Sample Mean (x̄)

Std Dev (σ or s)

Sample Size (n)

Confidence Level

Confidence Interval

(0, 0)

Margin of Error

Standard Error

Lower Bound

Upper Bound

CI = x̄ ± z × (σ/√n)

Understanding Confidence Intervals

A 95% confidence interval means: if you repeated the sampling 100 times, about 95 of those intervals would contain the true population mean.

Z-scores.

Statistics.

Sample size.

Central tendency.

Probability.

Percentages.