Sample mean & standard deviation calculator
Summarize 2–500 measurements with mean, sample standard deviation, minimum, maximum and range.
Result
Inputs used
- Measurements (comma, space or newline separated; decimal point)
- 10.1, 10.2, 9.9, 10.0, 10.3
| Sample count | 5 |
|---|---|
| Mean | 10.1 |
| Sample standard deviation (n−1) | 0.158114 |
| Minimum | 9.9 |
| Maximum | 10.3 |
| Range | 0.4 |
This is the overall sample standard deviation, not a within-subgroup estimate. These summary statistics do not establish normality, independence or statistical control. GET inputs appear in the URL; use non-sensitive measurements.
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What it computes
The sample mean is the sum of measurements divided by their count. Sample standard deviation is the square root of the sum of squared deviations from the mean divided by n − 1. All results retain the measurement's original unit.
For 10.1, 10.2, 9.9, 10.0 and 10.3, the mean is 10.1, the sample standard deviation is 0.158114, and the range is 0.4. The calculator uses an incremental algorithm to reduce numerical cancellation for tightly clustered observations.
Input format
Separate values with commas, spaces, semicolons or newlines. Use a decimal point: 10.1, 10.2 means two observations. A decimal comma would be read as a separator. Scientific notation such as 1.01e1 is accepted. Units, headers and missing values must be removed deliberately; invalid tokens are rejected rather than silently skipped.
GET forms put measurements in the result URL. Use non-sensitive values. At most 500 measurements and 6,000 characters are accepted; shorter lists make more portable bookmarks.
Frequently asked questions
Is this the right sigma for Cpk?
This is an overall sample standard deviation. Use the overall Pp/Ppk option in the capability calculator unless you have a separately justified within-subgroup estimate.
Does zero standard deviation mean a perfect process?
It means the entered values are identical. Check rounding, resolution, sampling and the measurement system before drawing a process conclusion.
Go deeper
Cite this page: Sample mean & standard deviation calculator
, Shopfloor. https://shopfloor.space/tools/sample-statistics-calculator/