Then he tried calculating the average standard deviation by doing the same thing. He added the three standard deviations and divided them by three to get an average of 5.1.

How to calculate Standard Deviation in Excel The Standard Deviation is a term used in statistics. The term describes how much the numbers if a set of data vary from the mean.

Key Points Use Excel to calculate daily returns and standard deviation to gauge stock volatility. Annualize volatility by multiplying daily standard deviation by the square root of 252.