Numbers, Units & Calculators
Sample Standard Deviation Calculator
Calculate sample standard deviation, variance, mean, and standard error of the mean. Inspect the n minus 1 denominator and sample count.
Sample variance divides squared deviations from the mean by n − 1. Standard deviation takes its square root.
The result includes count, mean, variance, standard deviation, and standard error.
- Measure the spread of a sample, such as 8 parts measured from a production run.
Calculate spread for eight observations
Input: 2, 4, 4, 4, 5, 5, 7, 9
Settings: Eight values; the sample formula divides by 7.
Result: sampleStandardDeviation 2.138089935299395; sampleVariance 4.571428571428572; mean 5; denominator 7.
The deviations from 5 are -3, -1, -1, -1, 0, 0, 2, and 4. Their squares sum to 32, and √(32 ÷ 7) ≈ 2.1381. The population formula gives √(32 ÷ 8) = 2.
Enter the sample and read the six result fields
- Enter observations separated by commas, spaces, semicolons, or line breaks.
- Use the same measurement unit throughout.
- Select Calculate and confirm the parsed count.
Sample assumptions and numeric bounds
- Commas split values, including commas inside thousands-formatted numbers.
- Floating-point arithmetic can introduce small rounding differences.
- Use population standard deviation when the observations form the complete population.