Confidence Interval Calculator

Calculate confidence intervals for means, proportions, and differences with statistical analysis

Data Input

Data Type

Confidence Level (%)

Sample Mean (x̄)

Sample Standard Deviation (s)

Sample Size (n)

Known population standard deviation (σ)

Enter your data and click Calculate to see the confidence interval

• Confidence level = certainty

• CI contains true parameter

• Narrower CI = more precise

• Higher confidence = wider CI

• Estimate population parameters

• Compare groups

• Assess precision

• Make decisions

• Random sampling

• Normal distribution

• Independent observations

• Adequate sample size