Author: Oscar Cronquist Article last updated on May 11, 2022

The CONFIDENCE.T function calculates the confidence range for a population mean using a Student's t distribution.

Formula in cell C7:


Excel Function Syntax



alpha Required. The significance level.
standard_dev Required. The standard deviation.
size Required. The number of samples.


The CONFIDENCE.T function returns:

  • #VALUE! error value if any argument is non-numeric.
  • #NUM! error value if
    • alpha <= 0 (zero)
    • alpha >= 1.
    • standard_dev <= 0.
    • size < 1.
  • #DIV/0! error value if size equals 1.

CONFIDENCE.T function truncates size argument to integers.