T-Confidence Interval Calculator
Enter the sample mean, sample standard deviation, sample size, and confidence level to calculate the t confidence interval.
* Note: The t confidence interval is used when the population standard deviation is unknown.
Step 1: Enter Parameters
e.g., 0
e.g., 1
e.g., 30
e.g., 95 for 95% confidence
How It Works
The t confidence interval for the mean is calculated as: $$ \bar{x} \pm t_{\alpha/2, \, n-1} \cdot \frac{s}{\sqrt{n}}, $$ where \( t_{\alpha/2, \, n-1} \) is the critical value from the Student’s t-distribution with \( n-1 \) degrees of freedom.
This interval is used when the population standard deviation is unknown.