Percentage Error Calculator

Why Use This Calculator?

This percentage error calculator gives you a clear accuracy check. It compares an expected value with your measured result. It shows the formula it uses for full transparency. It includes a Reset button for a fresh start.

How It Works

Enter the expected value and your observed value. The calculator applies this formula. Percentage error equals the absolute value of measured minus actual. Divide that by actual and multiply by 100 percent. The result shows with two decimal places. You will see a short note that explains the size of the error.

• Actual or Expected Value means the true or target value from a trusted source. Use a nonzero number.
• Measured or Observed Value means the value you recorded in your test or report.

You will get these results.

• Percentage error as a percent with two decimals.
• The same formula with your numbers filled in.
• A note that rates accuracy by range.
• A note that states higher or lower with the percent gap.

How to read the ranges.

• 0 percent means an exact match.
• Under 1 percent means extremely close accuracy.
• 1 to under 5 percent means good accuracy for most cases.
• 5 to under 10 percent means moderate accuracy.
• 10 to under 20 percent means low accuracy that needs work.
• 20 percent or more means a large gap that needs review.

How to Use This Tool

1. Type the Actual or Expected Value.
2. Type the Measured or Observed Value.
3. Click Calculate or press Enter.
4. Read the Percentage Error result.
5. Review the interpretation note.
6. Click Reset to clear the form.

Real World Benefits

Use this percentage error calculator for work, study, or quick checks.

• Physics labs compare a measured mass to a standard weight.
• Chemistry work checks expected concentration against the measured result.
• Quality control teams check part length against the spec sheet.
• Finance teams compare forecast sales against actual sales.
• Engineers calibrate a sensor reading against a reference value.
• Teachers and students get fast feedback on homework answers.

Example. Target equals 100 and measured equals 98. Percentage error equals 2 percent.

Tips for Getting the Best Results

These notes help you get precise results.

• Use numbers in both fields.
• Match units for both values.
• Use a nonzero actual value to avoid division by zero.
• The main result uses absolute error.
• The note states if measured is higher or lower.
• The output rounds to two decimals.
• Press Enter to run the calculation fast.
• Use Reset to clear values and messages.

This percentage error calculator keeps your checks quick and clear. It shows the math and the context on one screen. Run a test now with your numbers. Clean result, zero fuss.