STDEV.S measures how far values typically sit from the average (sample standard deviation). A small value means consistent; a large one means volatile.
Syntax
=STDEV.S(number1, [number2], ...)
Argument
What it means
number1
A sample of values.
Examples
Example 1
=STDEV.S(C2:C31)
Daily sales variability.
Example 2
=STDEV.S(C2:C31)/AVERAGE(C2:C31)
Coefficient of variation — compare volatility of stores of different sizes.
💡 Use STDEV.P only when you have the whole population (every value that exists), not a sample.
