1. What is Relative Percent Error?

Definition: Relative percent error measures the accuracy of a measurement by comparing the difference between measured and true values relative to the true value.

Purpose: It quantifies measurement accuracy as a percentage, making it easier to compare errors across different scales.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Measured — The experimentally determined value
• True — The actual or accepted reference value

Note: The true value cannot be zero (division by zero is undefined).

3. Interpretation of Results

Guidelines:

• 0-1%: Excellent accuracy
• 1-5%: Good accuracy
• 5-10%: Fair accuracy
• >10%: May need improvement

4. Using the Calculator

Tips: Enter both measured and true values. The calculator will automatically compute the relative percent error.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between absolute and relative error?
A: Absolute error gives the magnitude of difference, while relative error shows this difference relative to the true value.

Q2: Can relative error be negative?
A: No, the absolute value ensures it's always positive (0-100% range).

Q3: What if my true value is zero?
A: Relative error is undefined when true value is zero. Use absolute error instead.

Q4: When is relative error most useful?
A: When comparing measurements of different magnitudes or when the true value varies significantly.

Q5: How can I reduce relative error?
A: Improve measurement techniques, use more precise instruments, or take multiple measurements.