To find the variance for a measure in tableau, right click on the measure and select variance:
Note: The variance calculates the dispersion or spread of data. When data points are close together, the variance is low. When data points are more spread out, the standard deviation is high.
How does tableau calculate variance? Variance is the standard deviation squared.
Note: For those with an Excel bacgkround, tableau uses Excel's VAR.S by default.