# Percent Error Calculator

**Percent Error Calculator** is a free online tool that helps to find percent error in true value.

## What is a Percent Error Calculator?

A 'Percent Error Calculator' is an online tool which finds the percentage error for two given readings. In 'Percent Error Calculator', enter the observed value and the true value to find the percentage error within a few seconds.

### Percent Error Calculator

## How to Use the Percent Error Calculator?

Follow these steps which will help you to use the calculator.

**Step 1**: Enter the observed value and the true value in the input boxes.**Step 2**: Click on "**Calculate**" to find the percentage error.**Step 3**: Click on "**Reset**" to clear the fields and enter the new values.

## How to Calculate Percent Error?

When we measure or take any reading through a measuring instrument, we often find the reading to be different from the actual value. Here, one reading is an observed value (estimated measured value) and the other is the true value (theoretical actual value). Percentage error helps in calculating the difference in the readings to know how close the observed value is to the true value of an experiment. The following formula is used to calculate the percentage error between the two values or readings.

**Percent Error = [(Observed Value - True Value)/True Value] × 100**

Let us learn how to calculate the percentage error with the help of the following example.

## Solved Examples on Percent Error Calculator

**Example 1:**

In an experiment of measuring the boiling point of water, you get a reading of 101.5°C. This is considered to be the estimated measured value (Observed Value). The actual boiling point of water is 100°C, so this is considered to be the theoretical actual value (True Value). Find the % error between the estimated measured value and the theoretical actual value.

**Solution: **

To calculate the percent error we will use the formula:

Percent Error = [(Observed Value - True Value)/True Value] × 100

= [(101.5 - 100)/100] × 100

= 1.5/100 × 100

= 1.5%

Therefore, the percentage error is 1.5%.

**Example 2:**

In an experiment of measuring the boiling point of water, you get a reading of 140.7°C. This is considered to be the estimated measured value (Observed Value). The actual boiling point of water is 100°C, so this is considered to be the theoretical actual value (True Value). Find the % error between the estimated measured value and the theoretical actual value.

**Solution: **

To calculate the percent error we will use the formula:

Percent Error = [(Observed Value - True Value)/True Value] × 100

= [(140.7 - 100)/100] × 100

= 40.7/100 × 100

= 40.7%

Therefore, the percentage error is 40.7%.

Now, use the calculator to find the percent error for the following readings.

- Observed Value: 27, True Value: 29
- Observed Value: 180, True Value: 184

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