Percent Error Calculator

Calculate the percent error between experimental and theoretical values. Perfect for science experiments, quality control, and measurement analysis.

Percent Error Calculator

Calculate the percent error between experimental and theoretical values using the formula:

% error = |((E - T) / T)| × 100

Results

Percent Error
10.00%
Absolute Error
0.2000
Relative Error
0.1000

Formula Used

The percent error is calculated using this formula:

Percent Error = |((Experimental - Theoretical) / Theoretical)| × 100

What is Percent Error?

Percent error measures how far off your measured or experimental value is from the true, expected value. It's expressed as a percentage of the true value, making it easy to understand the magnitude of the difference.

Everyday Example

Imagine you're baking cookies and the recipe calls for 2 cups of flour. After measuring, you actually used 2.2 cups. Here's how to find the percent error:

  • Experimental (measured) value: 2.2 cups
  • Theoretical (recipe) value: 2.0 cups
  • Difference: 0.2 cups
  • Percent Error: (0.2 ÷ 2.0) × 100 = 10%

What the Calculator Finds

Main Results

  • Percent Error: The relative size of the error
  • Absolute Error: The actual size of the difference
  • Relative Error: The error ratio (before converting to percent)

Key Features

  • Always shows positive percentages
  • Works with any unit of measurement
  • Handles both over and under estimates
  • Shows step-by-step calculations

Real-World Applications

Scientific Research & Laboratory Work

Chemistry Lab Analysis

  • Measuring chemical concentrations in solutions
  • Determining atomic mass in experiments
  • Analyzing reaction yields
  • Verifying pH measurements

Physics Experiments

  • Gravitational acceleration measurements
  • Electrical resistance calculations
  • Wave frequency analysis
  • Velocity and momentum studies

Industrial & Manufacturing

Quality Control

  • Product dimension tolerances
  • Weight consistency checks
  • Temperature control systems
  • Chemical composition verification

Process Validation

  • Equipment calibration
  • Production line efficiency
  • Material strength testing
  • Batch consistency analysis

Educational & Research

Student Labs

  • Physics experiment validation
  • Chemistry measurement accuracy
  • Biology data analysis
  • Engineering project calculations

Research Validation

  • Experimental data verification
  • Measurement precision analysis
  • Statistical error assessment
  • Methodology accuracy checks

How It Works

Example Calculation

Boiling Point Measurement

  • Experimental Value: 101.5°C
  • Theoretical Value: 100.0°C
  • Absolute Error: |101.5 - 100| = 1.5°C
  • Relative Error: |1.5/100| = 0.015
  • Percent Error: 0.015 × 100 = 1.5%

Mass Measurement

  • Experimental Value: 52.3g
  • Theoretical Value: 50.0g
  • Absolute Error: |52.3 - 50| = 2.3g
  • Relative Error: |2.3/50| = 0.046
  • Percent Error: 0.046 × 100 = 4.6%

Common Applications

Science & Engineering

  • Laboratory measurements
  • Quality control testing
  • Experimental data analysis
  • Instrument calibration
  • Material testing

Education & Research

  • Student lab reports
  • Research validation
  • Data accuracy assessment
  • Method comparison
  • Error analysis

Important Notes

  • The theoretical value cannot be zero (division by zero)
  • Percent error is always positive (absolute value)
  • Results are rounded to 2 decimal places for percent error
  • Absolute and relative errors are shown to 4 decimal places
  • Both positive and negative values are supported