1. What is Error Ratio?

The Error Ratio measures the relative difference between an actual (true) value and a measured (observed) value. It indicates how much a measurement deviates from the true value, expressed as a ratio or percentage.

2. How Does the Calculator Work?

The calculator uses the Error Ratio formula:

Where:

• \( Actual \) — The true or reference value
• \( Measured \) — The observed or measured value

Explanation: The formula calculates the proportional difference between the actual and measured values. A positive result indicates the measured value is lower than actual, while a negative result indicates it's higher.

3. Importance of Error Ratio

Details: Error Ratio is crucial in quality control, scientific measurements, and engineering to assess the accuracy of instruments and methods. It helps quantify measurement reliability and identify systematic errors.

4. Using the Calculator

Tips: Enter the actual (true) value and measured value in the same units. The actual value must be greater than zero. Results are shown as both a ratio and percentage.

5. Frequently Asked Questions (FAQ)

Q1: What does a zero error ratio mean?
A: A zero error ratio means perfect measurement - the measured value exactly matches the actual value.

Q2: How is error ratio different from percent error?
A: Error ratio is the fractional difference, while percent error is the same value multiplied by 100. This calculator shows both.

Q3: Can error ratio be negative?
A: Yes, a negative error ratio indicates the measured value is greater than the actual value.

Q4: What's considered an acceptable error ratio?
A: Acceptable ranges vary by field. In many scientific applications, error ratios below ±0.05 (5%) are considered good.

Q5: When shouldn't this formula be used?
A: When the actual value is zero (division by zero) or when dealing with logarithmic or ratio scales that require different error calculations.