Percentage Error Calculator
Calculate percentage error, percentage difference, and percentage change between two values.
Related Tools
0 comments
How it works
Choose the type of calculation: percentage error (how far an experimental value is from the true value), percentage difference (difference between two values relative to their average), or percentage change (increase or decrease from an old to a new value). The tool applies the appropriate formula and shows the result with sign to indicate direction. All computation runs locally.
% Error = |Estimated − Actual| / |Actual| × 100
Common use cases
- Checking the accuracy of a measurement against a known standard in a lab.
- Calculating how much a price, population, or metric changed between two periods.
- Comparing two experimental results when neither is the "true" value.
Frequently asked questions
What is the difference between percentage error and percentage difference?
Percentage error compares to a known correct value. Percentage difference compares two values with no known "correct" one, using their average as the denominator.
Can the percentage error be negative?
The absolute formula gives a positive result. If you need signed error (to know if the estimate is too high or too low), the tool provides both the signed and unsigned result.