Standard deviation calculator

Paste a data set and get the full statistical picture: σ and s, variance, mean, median, mode, quartiles, IQR, coefficient of variation, and Tukey outlier fences.

How to Standard deviation calculator

1. Step 1. Paste numbers separated by commas, spaces, or semicolons.
2. Step 2. Choose population (σ, divide by n) or sample (s, divide by n−1) mode.
3. Step 3. Review standard deviation, variance, mean, and median.
4. Step 4. Open the summary for quartiles, IQR, CV, and outlier fences.

Frequently asked questions

Population or sample standard deviation?

Use sample (n−1) when your data is a subset of a larger population — the usual case. Use population (n) only when you have every member.

What does standard deviation tell me?

The typical distance of data points from the mean. Small σ means values cluster tightly; large σ means they are spread out.

What are outlier fences?

Tukey’s rule: values below Q1 − 1.5×IQR or above Q3 + 1.5×IQR are flagged as potential outliers — the rule behind boxplots.