Standard Deviation Calculator
Standard deviation measures how spread out a set of numbers is around its average. Paste or type your numbers to get sample and population standard deviation along with the mean, median and mode.
Type a number and the answer appears straight away.
Your answer
Sample standard deviation5.23723
- Population standard deviation
- 4.89898
- Mean
- 18
- Median
- 18.5
- Mode
- 23
- Range
- 10 to 23
- Sample variance
- 27.4286
- Count / sum
- 8 / 144
The math behind it: Standard Deviation
s = √( Σ(x - mean)² / (n - 1) )
Use the sample figure (dividing by n - 1) when your numbers are a sample from a larger group, which is the usual case. Use the population figure (dividing by n) only when you have every member of the group.
You might also need
Checked and updated: