When to use this calculator
Compare absolute measurement error with a positive reference value. A reference of zero does not have a defined relative error.
Explore the descriptive statistics calculators for other questions in this topic. For a related calculation, use the Root Mean Square Calculator: Calculate RMS for four equally weighted observations.
PUTTING IT INTO PRACTICE
Relative Error: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Measured value | 102 |
| Reference value | 100 |
| Result | 2 % |
- Check the input labels and enter the example values above.
- Apply the relationship: Relative error (%) = |measured − reference| ÷ reference × 100.
- The result is 2 %, rounded for display.
How to interpret your result
A reference of zero does not have a defined relative error.
The mean, median, range and standard-deviation tools accept variable-length lists with their limits stated. Choose a sample or population denominator appropriately. A summary statistic does not validate the sampling process or explain causation.
Frequently asked questions
Should I use sample or population standard deviation?
Use population deviation for the complete population being described. Use the sample form when estimating variability from a sample under suitable assumptions.
How do I use the relative error calculator?
Enter measured value, reference value. The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Relative error (%) = |measured − reference| ÷ reference × 100.
What should I check before using the result?
A reference of zero does not have a defined relative error.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
Further reading
For background on this topic, see NIST: exploratory data analysis ↗. This is a topic reference, not an external review or endorsement of this tool.
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