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.
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Direct answer
What Sample Standard Deviation Calculator does
Sample standard deviation describes the spread of observations around their mean. It uses the sum of squared deviations divided by n minus 1, followed by a square root. It differs from population standard deviation, which divides by n.
Output
What you receive
The result contains sample standard deviation, sample variance, mean, count, n minus 1, and standard error of the mean.
Use this tool
How to calculate sample standard deviation
- Enter at least two numeric observations.
- Keep the same measurement unit for every observation.
- Select Calculate and inspect the mean, variance, standard deviation, and denominator.
Processing
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The calculator processes your values locally. It does not send them to a calculation service.
Worked example
Test Sample Standard Deviation Calculator with a safe sample
Input: 2, 4, 4, 4, 5, 5, 7, 9
Settings: Sample calculation with 8 observations.
Expected result
Mean 5; sample variance approximately 4.5714285714; sample standard deviation approximately 2.1380899353.
Squared deviations sum to 32. Divide by 7, then take the square root. The population deviation would be 2.
Limits
Check before you use the result
- Enter up to 1000 values separated by commas, spaces, line breaks, or semicolons. Use a dot for decimal fractions.
- Each nonzero input must have absolute value from 1e-100 through 1e100. Commas separate values, not thousands: 1,000 means two values. Fraction expressions and percentages are not accepted.
- Calculations use floating-point numbers. Results can include rounding; closely spaced large integers can become indistinguishable during parsing.
- At least two observations are required. Missing observations need an explicit decision before entry.
- Standard error assumes independent observations from a population with finite variance. This formula does not adjust for correlated or weighted samples.
- Standard deviation describes spread. It does not prove normality, independence, or statistical significance. This tool does not calculate confidence intervals.