Relative Standard Deviation Calculator
Relative standard deviation expresses the standard deviation in relation to a positive mean, making spread easier to compare across similar measurements.
How to use this calculator
- Enter a positive mean and a non-negative standard deviation.
- Confirm that all inputs use the stated units and the same population, period or scope.
- Change one assumption at a time when comparing scenarios.
Formula used by the relative standard deviation calculator
RSD = standard deviation ÷ mean × 100%
- RSD = standard deviation ÷ mean × 100%
- RSD becomes unhelpful near a zero mean and comparisons require compatible measurement methods.
- Inputs are validated against required ranges and outputs are rounded for readability.
Worked examples
Worked example
Mean 12.5 and standard deviation 1.2.
RSD is 9.6%.
RSD is 9.6%.
Understanding the result
Relative standard deviation expresses the standard deviation in relation to a positive mean, making spread easier to compare across similar measurements.
RSD becomes unhelpful near a zero mean and comparisons require compatible measurement methods.
Important notes
RSD becomes unhelpful near a zero mean and comparisons require compatible measurement methods.
Use the result as a calculation aid for the inputs supplied; confirm critical specifications independently.
Frequently asked questions
Is RSD the same as coefficient of variation?
It is commonly expressed as the coefficient of variation in percent form.
Can I compare unrelated measurements?
Only carefully; units and underlying populations must be comparable.
How do I use this calculator?
Enter a positive mean and a non-negative standard deviation.
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Related calculators
- Standard Deviation Calculator — Calculate population or sample standard deviation, variance, mean, sum, and count.
- Coefficient of Variation Calculator — Calculate the population coefficient of variation from a numeric data set with a positive mean.
- Pooled Standard Deviation Calculator — Combine two sample standard deviations into a pooled estimate when the equal-variance assumption is appropriate.
- Mean Absolute Deviation Calculator — Measure the average absolute distance of data values from their arithmetic mean.
- Standard Error Calculator — Estimate the standard error of a sample mean from sample standard deviation and sample size.
- Median Absolute Deviation Calculator — Calculate raw median absolute deviation and mean absolute deviation from the data median.
Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
- How to Calculate a Z-Score — Learn how a z-score shows how far a value is from the mean in standard-deviation units.
- How to Calculate Standard Deviation — Learn what standard deviation measures, the population and sample formulas, and how to interpret the result.
- Z-Score — Learn what a z-score measures and how it describes a value relative to a mean and standard deviation.
This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.