Power Calculators

⚠️ Percentage Error Calculator

Calculate percentage error by comparing an experimental or measured value with a reference or accepted value.

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Enter details

Use the accepted or reference value as the denominator.

Fill in the details and click Calculate to see your results.


Also available in our Android app, with charts and full breakdown tables.

📘 About the Percentage Error

Percentage error is commonly used to compare a measured or experimental result with an accepted or reference value.

The absolute percentage error reports the magnitude of the discrepancy without its direction.

🧮 Formula

Absolute error
Absolute error = |Measured − Accepted|
Percentage error
Percentage error = |Measured − Accepted| ÷ |Accepted| × 100

Where

  • Measured = observed or experimental value
  • Accepted = reference or accepted value
The accepted value should be non-zero for a meaningful percentage error.

✏️ Worked example

Measured 98, accepted 100

You enter
Measured Value98
Accepted Value100
You get
Absolute Error2
Percentage Error2.00%
Signed Relative Error-2.00%

The absolute percentage error is 2.00%.

Try this example →

🧭 How to use this calculator

What you enter

  • Measured Value
  • Accepted ValueUse the accepted or reference value as the denominator.

What you get

  • Absolute Error
  • Percentage Error
  • Signed Relative Error

💡 Where it is used

  • Laboratory measurements.
  • Physics and chemistry experiments.
  • Comparing approximations with known values.
  • Checking numerical results.

❓ Frequently asked questions

What is percentage error?

It is the absolute difference between measured and accepted values divided by the absolute accepted value, multiplied by 100.

Can percentage error be negative?

The standard absolute percentage error is non-negative. This calculator also shows signed relative error separately.