Percent error shows how far a measured value is from the true value.
Percent error shows how far a measured value is from the true value.
This calculator helps you compute the percent error and absolute error between a measured value and a true (actual) value. Simply enter the true value and observed value, and it automatically calculates the errors and gives an easy-to-understand result.
Provide the values for:
The calculator updates the results as you type.
The calculator performs:
Results are shown instantly in a clear format.
The calculator ensures reliable results:
This makes it safe and beginner-friendly for learning.
The results appear instantly:
1. Enter the true value (TV) and observed value (OV) in the input fields.
2. The calculator computes the absolute error:
Absolute Error = |OV − TV|
3. It then calculates the percent error:
Percent Error = (Absolute Error ÷ TV) × 100%
4. The result section displays:
• Absolute error
• Percent error
• Whether the observed value is higher, lower, or equal to the true value
5. Invalid inputs or division by zero trigger a clear error message.
This allows students, engineers, and beginners to quickly verify measurement accuracy and understand deviations visually.
Suppose the true value of a measurement is:
100
And the observed value is:
95
The calculator computes:
Absolute Error = |95 − 100| = 5
Percent Error = (5 ÷ 100) × 100% = 5%
Observed value is lower than the true value
You can change the inputs to instantly see updated errors and results.
Learn how to calculate percent error, understand absolute error, and get accurate results using our online tool.
This calculator computes the percent error and absolute error between a true (actual) value and an observed (measured) value. It instantly shows how far your measured value is from the true value.
Enter the true value in the “True Value” field and the observed value in the “Observed Value” field. The calculator will automatically display the absolute error and the percent error along with a description of the difference.
Yes! The Percent Error Calculator is completely free with no registration or hidden charges.
Yes, negative values are allowed for observed values. However, the true value must not be zero, as percent error cannot be calculated when dividing by zero.
It calculates absolute error as |Observed − True| and percent error as (|Observed − True| ÷ True) × 100. The results are displayed in real-time.
If the true value is zero or if inputs are not numbers, the calculator will display an error message and will not calculate percent error.
Yes, use the “Clear All” button to reset the input fields or the “Reload Calculator” button to reload the page and clear all results.
Yes, the calculator is fully responsive and works well on smartphones, tablets, laptops, and desktops.
Results are rounded to two decimal places, providing clear and accurate percent error and absolute error values.
Students, teachers, and anyone performing measurements or experiments can use this tool to quickly calculate percent error and understand measurement accuracy.
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