Percent Error Calculator

Calculate the percent error between a measured value and the actual (theoretical) value. This tool is commonly used in science experiments, measurements, and quality control to determine the accuracy of measurements.

How to Use This Calculator

1. Enter your measured value - the value you obtained from your experiment or measurement
2. Enter the actual value - the true, theoretical, or accepted value
3. Click "Calculate Percent Error" to see your results
4. The calculator will display both the absolute error and percent error

Understanding Percent Error

Percent error is a measure of how accurate a measurement is compared to the true or accepted value. It's calculated using the formula:

Percent Error = |Measured Value - Actual Value| / |Actual Value| × 100%

What is Absolute Error?

Absolute error is the difference between the measured value and the actual value. It represents the magnitude of error without considering direction:

Absolute Error = |Measured Value - Actual Value|

Applications

• Scientific Experiments: Evaluate the accuracy of experimental results
• Quality Control: Assess manufacturing precision and product quality
• Laboratory Work: Validate measurement techniques and equipment
• Education: Learn about measurement accuracy and experimental error
• Engineering: Verify design specifications and tolerances

Interpreting Results

• Low Percent Error (0-5%): Excellent accuracy, measurement is very close to actual value
• Moderate Percent Error (5-15%): Good accuracy, acceptable for most applications
• High Percent Error (>15%): Poor accuracy, may indicate measurement problems or systematic errors

Important Notes

• Percent error cannot be calculated if the actual value is zero (division by zero)
• The result is always expressed as a positive percentage
• Lower percent error indicates higher accuracy
• Percent error does not indicate whether the measurement was too high or too low