Percentage Error Calculator

Percentage Error Calculator | Math Tools

Percentage Error Calculator

Calculate the percentage error between an experimental (measured) value and the true (accepted) value. Enter the values below.

What Is Percentage Error?

Percentage error quantifies how inaccurate a measurement is compared to the true value, expressed as a percentage. It shows the size of the error relative to the accepted value.

Percentage Error Formula

The formula used to calculate percentage error is:

Percentage Error = (|Experimental Value − True Value| / True Value) × 100%

  • True Value: The accepted or correct value
  • Experimental Value: The measured or observed value
  • |…|: Absolute value, to ignore negative sign

Example

Example: The true length of an object is 50 cm. The measured length is 47 cm.

The percentage error is:

(|47 − 50| / 50) × 100% = (3 / 50) × 100% = 6%

This means there is a 6% error in the measurement.

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