Percent Error Calculator

Calculate Percent Error

Quick Examples:

Error Analysis Results

Absolute Error:

Percent Error Formula

Percent Error =

|Experimental Value - Theoretical Value|

Theoretical Value

× 100%

Where:

Experimental Value = Your measured result
Theoretical Value = Expected or accepted value
Absolute value ensures positive result

How to Use This Calculator

Enter experimental value - the result you measured or observed

Enter theoretical value - the accepted or expected result

Choose decimal precision for your result display

Click calculate to see percent error and accuracy level

Try quick examples to understand different scenarios

About the Percent Error Calculator

What is Percent Error?

Percent error is a measure of how inaccurate a measurement is, standardized to how large the measurement is. It's calculated as the absolute difference between the experimental and theoretical values, divided by the theoretical value, then multiplied by 100 to get a percentage.

When to Use Percent Error:

Scientific experiments and lab reports
Quality control in manufacturing
Comparing measured vs. expected values
Academic research and data analysis
Engineering tolerance calculations

Accuracy Levels:

Excellent (0-2%): Very high accuracy

Good (2-5%): High accuracy

Fair (5-10%): Moderate accuracy

Poor (>10%): Low accuracy

Common Applications:

Physics experiments (gravity, motion, etc.)
Chemistry lab measurements
Statistical analysis
Medical diagnostics
Financial forecasting accuracy

Understanding Your Results

Absolute Error

The actual difference between your measured and expected values, regardless of sign.

Percent Error

The relative error expressed as a percentage, showing how far off your measurement is proportionally.

Accuracy Level

A qualitative assessment of your measurement's precision based on the percent error value.