Percentage Error Calculator
Calculate absolute percentage error from an accepted reference value and an observed value.
A QUICK WALKTHROUGH
How to use this tool
- Enter finite values in consistent units.
- Review the stated formula and input definitions.
- Calculate locally in this browser.
Formula and limits
Absolute percentage error = |observed − reference| ÷ |reference| × 100. Reference cannot be zero.
Scope
This is a bounded arithmetic aid, not a measurement, diagnosis, engineering design, or recommendation. Verify source values, units, and assumptions independently.
Privacy
Inputs are processed in this browser and are not uploaded or stored.
GOOD TO KNOW
Common questions
Does this make a decision for me?
No. It only evaluates the stated formula using your inputs.