Math

Percent Error

What is the Percent Error?

Accuracy of a measurement

This formula is widely used in math applications. Understanding when and how to apply it helps you interpret calculator results correctly and catch input errors before they propagate.

Formula

% error = |expected-actual|/|expected|*100

Substitute known values into the formula above. Ensure all variables use consistent units before calculating.

Worked Example

Use percent error calculator

Use the linked calculator below to try your own values and see step-by-step working.

When to Use This Formula

Apply the Percent Error when you need to accuracy of a measurement. It is a standard reference in math coursework, professional practice, and our linked calculators.

Tips & Common Mistakes

  • Apply order of operations (PEMDAS) consistently.
  • Round only at the final step unless instructed otherwise.
  • Always verify critical results independently for engineering, medical, or legal applications.

Further Reading

Browse the Formula Library for related formulas, or read educational articles on our Blog.