Percent Error Calculator
Calculate percentage error between experimental and theoretical values with step-by-step calculations. Perfect for science experiments, data analysis, and quality control applications.
Percentage Error Calculator
Common Percent Error Examples
Click on these links to see instant calculations with common experimental scenarios:
Percent Error
Percent error measures the accuracy of experimental measurements by comparing them to theoretical or accepted values. It's essential in scientific research, quality control, and data validation.
Percent Error Formula
Where: |x| represents absolute value
Example: |9.8 - 10.0| / |10.0| × 100% = 2%
Error Interpretation Guidelines
| Percent Error Range | Accuracy Level | Interpretation | Example |
|---|---|---|---|
| 0% - 5% | Excellent | Very accurate measurement | Laboratory precision |
| 5% - 10% | Good | Acceptable for most purposes | Field measurements |
| 10% - 20% | Fair | May need improvement | Rough estimates |
| 20% - 50% | Poor | Significant measurement issues | Systematic errors |
| Above 50% | Very Poor | Major problems present | Equipment malfunction |
- Science Experiments: Validate experimental results against theoretical predictions
- Quality Control: Assess manufacturing precision and product consistency
- Data Analysis: Evaluate measurement accuracy and identify systematic errors
- Engineering: Verify design calculations and prototype performance
- Education: Teach measurement accuracy and experimental methodology
Frequently Asked Questions
What is percent error?
Percent error is a measure of how inaccurate a measurement is, calculated as the absolute difference between experimental and theoretical values divided by the theoretical value, multiplied by 100%.
How do you calculate percent error?
Percent Error = |Experimental Value - Theoretical Value| / |Theoretical Value| × 100%. The absolute value ensures the result is always positive.
What is a good percent error?
Generally, percent error less than 5% is considered excellent, 5-10% is good, 10-20% is acceptable, and above 20% may indicate significant measurement issues or systematic errors.