Calculate the percentage error between your experimental value and the theoretical (accepted) value with step-by-step working.
Percentage Error = |Experimental - Theoretical| / |Theoretical| × 100%
Where:
Absolute Error = |Experimental - Theoretical|
Relative Error = |Experimental - Theoretical| / |Theoretical|
Percentage error measures how accurate an experimental value is compared to the theoretical (accepted) value. It expresses the difference as a percentage of the theoretical value, making it easy to compare errors across different scales.
Absolute value ensures the error is always positive, regardless of whether the experimental value is higher or lower than the theoretical value. This focuses on the magnitude of the error rather than its direction.
Acceptable percentage error depends on the field and context. In physics experiments, errors under 5% are often considered good. In chemistry, 1-2% might be expected. In social sciences, larger errors may be acceptable. Always consider the context of your measurement.
Yes, percentage error can exceed 100% if the experimental value is more than double the theoretical value (or less than zero for positive theoretical values). This indicates a very large discrepancy between measured and expected values.
Percentage error is undefined when the theoretical value is zero because you cannot divide by zero. In such cases, use absolute error instead, or consider whether the measurement is meaningful when the expected value is zero.
