Percent Error Calculator

Find how far a measured or experimental value is from the accepted value, as a percentage.

Fractions and decimals both work.
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Percent Error
Absolute error
Signed error
Accuracy
Work

Saved Calculations

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How to Calculate Percent Error

Percent error compares a measurement with the known or accepted value, using the accepted value as the base.

Percent error = |measured − true| ÷ |true| × 100

Worked Example

Tips

Some classes keep the sign (without the absolute value bars) to show whether a result was high or low; this page shows both. Round the answer to the precision of your measurement.