Confidence Interval Calculator

Confidence Level:

Sample Size (n):

Please enter a valid sample size greater than 0

Sample Mean (x̄):

Please enter a valid sample mean

Standard Deviation (σ):

Please enter a valid standard deviation greater than 0

Results:

Confidence Interval:

Lower Bound:

Upper Bound:

Margin of Error:

Understanding Confidence Intervals

A confidence interval provides a range of values that likely contains an unknown population parameter. It helps quantify the uncertainty in sample estimates.

How to Interpret Results

For example, a 95% confidence interval means if you were to repeat the sampling process many times, about 95% of the intervals would contain the true population parameter.

Key Components

Confidence Level: The probability that the interval contains the true population parameter
Sample Size: Number of observations in your sample
Sample Mean: Average value of your sample
Standard Deviation: Measure of variability in your data