Percent Error Calculator

Compare an experimental or estimated value with a true value and see absolute error, signed error, and percent error.

Observed / experimental value

Accepted / true value

—Absolute error

—Signed error

—Percent error

—Relative error

—Percent error = |observed − true| ÷ |true| × 100.

How to use this Percent Error Calculator

Calculate percent error between an observed and accepted value. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.