Relative Standard Deviation Calculator
Enter numeric observations to calculate the mean, standard deviation, and relative standard deviation (percentage).
Mean
19.5000
Std. deviation
5.6125
RSD
28.78%
How to Use This Calculator
- Enter the dataset values separated by spaces or commas.
- Review the computed mean and standard deviation.
- Use the relative standard deviation to express variability as a percentage of the mean.
- Compare RSD values across datasets to judge precision or consistency.
Formula
Mean μ = Σxi / n
Sample standard deviation s = √[Σ(xi − μ)² / (n − 1)]
Relative standard deviation = (s / μ) × 100%
RSD equals the coefficient of variation expressed as a percentage, emphasizing variability relative to the mean.
Full Description
Relative standard deviation (RSD) measures precision by scaling standard deviation to the mean. It is commonly used in analytical chemistry, laboratory calibration, and finance to compare variability across different magnitudes.
Lower RSD indicates tighter clustering around the mean, while higher values reveal more dispersion relative to the average level.
Frequently Asked Questions
Is RSD the same as coefficient of variation?
Yes. RSD is the coefficient of variation expressed in percentage form.
Can mean be zero?
If the mean is zero, RSD is undefined. The calculator reports 0 to avoid division by zero.
Which datasets benefit most from RSD?
Use RSD when comparing variability across datasets with different means or units.
Do I need sample or population standard deviation?
This calculator uses the sample standard deviation. For full populations, divide by n instead of n − 1.