Percentage Accuracy Calculator

How to Use This Calculator

1. Enter the Observed Value - this is the actual value you measured or obtained.
2. Enter the Expected Value - this is the true or accepted value.
3. Click the Calculate button to compute the percentage accuracy.
4. The calculator will display the percentage accuracy and the absolute error.

Understanding Percentage Accuracy

Percentage accuracy is a measure of how close a measured or calculated value is to the true or accepted value. It is expressed as a percentage and calculated using the formula:

Accuracy = 100 × |Observed - Expected| / |Expected|

Where:

• |Observed - Expected| is the absolute error (the absolute difference between the observed and expected values)
• |Expected| is the expected value

Interpreting Results

A percentage accuracy of 100% indicates a perfect match between the observed and expected values. Lower percentages indicate larger discrepancies. This calculator is particularly useful in fields such as:

• Science and research for measuring experimental accuracy
• Engineering for quality control
• Statistics for assessing measurement reliability
• Education for evaluating test results

Example

Suppose you measure a length of 102.5 cm, but the actual expected length is 100.0 cm:

1. Observed Value = 102.5 cm
2. Expected Value = 100.0 cm
3. Absolute Error = |102.5 - 100.0| = 2.5 cm
4. Percentage Accuracy = 100 × 2.5 / 100.0 = 25%

In this case, your measurement has a percentage accuracy of 25%, meaning it's 25% off from the expected value.