Percent Error Calculator
Calculate percentage error between observed and true values
Percent Error Calculator
Calculate the percentage error between an observed value and the true (expected) value. This calculator helps measure the discrepancy between measured and known values.
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đ Understanding Percentage Error
What is Percentage Error?
Percentage error is a measurement of the discrepancy between an observed (measured) and a true (expected, accepted, known) value.
Common Uses
Used to compare measured vs. known values and assess whether measurements taken are valid in scientific experiments.
Negative Values
This calculator shows negative values when the observed value is smaller than the true value, indicating the direction of error.
Computing Percentage Error
The computation of percentage error involves calculating the difference between the observed and the true value. The error is then divided by the true value, resulting in the relative error, which is multiplied by 100 to obtain the percentage error. This calculator preserves the sign to show whether the observed value is above (positive) or below (negative) the true value.
Negative Percentage Error
Based on the formula above, when the true value is positive, percentage error is always positive due to the absolute value. In most cases, only the error is important, and not the direction of the error. However, it is possible to have a negative percentage error.
This occurs if we do not take the absolute value of the error, the observed value is smaller than the true value, and the true value is positive. A negative percentage error simply means that the observed value is smaller than the true value. If the observed value is larger than the true value, the percentage error will be positive.
The best possible outcome for percentage error is that the observed and true values are equal, resulting in a percentage error of 0.