Percentage Error Formula:
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Definition: Percentage error measures the accuracy of an experimental value compared to a theoretical or accepted value.
Purpose: It quantifies the difference between measured and true values as a percentage of the true value.
The calculator uses the formula:
Where:
Key Points:
Applications: Used in scientific experiments, quality control, engineering, and any field requiring measurement accuracy assessment.
Instructions: Enter both experimental and theoretical values. The theoretical value must be non-zero.
Q1: What's considered a good percentage error?
A: This depends on the field. In many scientific experiments, <5% is good, while engineering might require <1%.
Q2: Can percentage error be negative?
A: No, the absolute value makes it always positive. The sign of (Experimental - Theoretical) indicates direction of error.
Q3: What if my theoretical value is zero?
A: Percentage error is undefined when theoretical value is zero. Use absolute error instead.
Q4: How is this different from percent difference?
A: Percent error compares to a known value, while percent difference compares two experimental values.
Q5: Should I use more decimal places?
A: Use decimal places appropriate for your measurement precision. The calculator shows 4 by default.