1. What is Percent Error?

Percent error is a measure of how inaccurate a measurement is, compared to the true or accepted value. It expresses the difference between the measured and true values as a percentage of the true value.

2. How Does the Calculator Work?

The calculator uses the percent error formula:

Where:

• \( \text{measured} \) — The experimentally measured value
• \( \text{true} \) — The true, theoretical, or accepted value

Explanation: The absolute difference between measured and true value is divided by the true value and multiplied by 100 to get a percentage.

3. Importance of Percent Error Calculation

Details: Percent error is crucial in scientific experiments to quantify the accuracy of measurements. It helps assess the reliability of experimental methods and results.

4. Using the Calculator

Tips: Enter both measured and true values. The true value cannot be zero (division by zero is undefined). Values can be positive or negative depending on the context.

5. Frequently Asked Questions (FAQ)

Q1: What is a good percent error value?
A: This depends on the field, but generally under 5% is considered good, while over 10% may indicate problems with the measurement.

Q2: Can percent error be negative?
A: No, the absolute value makes percent error always positive. The sign of (measured - true) indicates direction of error.

Q3: How is percent error different from percent difference?
A: Percent error compares to a known true value, while percent difference compares two experimental values.

Q4: What if my true value is zero?
A: Percent error is undefined when true value is zero. Consider using absolute error instead.

Q5: Why use absolute value in the formula?
A: Absolute value ensures the error is always expressed as a positive percentage, focusing on magnitude rather than direction.