Percentage error formula

The Percentage error formula serves as a valuable metric for assessing the precision of experimental or observational data. It quantifies the relative discrepancy between a measured and true value, presented as a percentage of the absolute true value. It is expressed as, Percentage error formula, expressed as
[ Observed Value - True Value | True Value | ] × 100

Percentage deviation

Percentage deviation is useful in various fields, including experimental sciences, quality control, and data analysis, to assess the degree of variation or discrepancy between measured or observed values and expected outcomes. Learn how to calculate and interpret percentage error for assessing accuracy and reliability in scientific data using our visual percentage error calculator.

Examples of percentage error

Join us in mastering the concept of Percentage Error, where precision meets scrutiny. Understand how to evaluate the accuracy of your measurements and calculations.
Example 1: Scientific Calibration
  • In a scientific instrument calibration, you record a temperature reading of 98.5°C, but the true temperature is 100°C. What is the percentage error in the measurement?
Example 2: Chemical Concentration
  • The concentration of a chemical solution is measured as 4.8 mol/L, but the true concentration is 5.0 mol/L. What is the percentage error in the measurement?
Example 3: Astronomical Observation
  • During stargazing, the measured brightness of a star is 2.7 magnitudes, but the true magnitude is 2.5. What is the percentage error in the observation?

Percentage error worksheet

Questions:
Calculate percentage error
1. If the observed value is 30 m/s and true value is 32 m/s?
2. If the observed value is 105 mL and true value is 100 mL ?
3. If the observed value is 45.7 kg and true value is 46 kg?
4. If the observed value is 400 meters and true value is 410 meters?
5. If the observed value is 90% and true value is 85%?
Answer Key:
[1- -6.25% , 2- 5% , 3- -0.65% , 4- -2.43% , 5- 5.88%]

Percentage error calculator FAQ

What is percentage error, and why is it important?
Percentage error is a measure of the accuracy of a measurement or calculation compared to an expected or theoretical value. It is important because it helps assess the reliability of data and the precision of experiments.
How is percentage error calculated?
Percentage error is calculated using the percentage error formula- Percentage error = [(Measured Value−True Value)/ |True Value|]× 100.
What are real-world examples for percentage error?
Percentage error is relevant in various fields, including physics, chemistry, engineering, manufacturing, quality control, and data analysis, where precise measurements and data accuracy are essential.
What does a negative percentage error indicate?
A negative percentage error indicates that the measured value is less than the expected value. It suggests an underestimation or an error in the negative direction.
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