In statistics, standard score is otherwise called as z-values, z scores, normal scores, and standardized variables. The z score helps us to compare scores with the bunch of data. It also tells us how far a particular score is away from the mean. Z-score is a measure of standard deviation. It also let us decide whether or not to reject the null hypothesis. Use this online calculator to find the z score value by entering the values, standardized random variable (X), sample mean and sample standard deviation.