Use our Standard Deviation calculator, a free online conversion tool to calculate and perform Standard Deviation of the numbers
x is the set of the numbers
x̄ or mean is the average of the set of the numbers
n is the size of the set
SD or σ is the standard deviation
It is difficult to understand the standard deviation solely from the standard deviation formula. There are two general interpretations that can be useful in understanding the standard deviation.
1. The standard deviation may be thought of as the average difference between an observation and the mean, ignoring the sign.
2. The standard deviation may be thought of as the average difference between any two data values, ignoring the sign.