## HOW TO CALCULATE THE PERCENTAGE ERROR?

**PERCENTAGE ERROR FORMULA:- M-A/A * 100**

- Where M = Measured value
- A= Actual value

## STEPS TO FIND OUT THE PERCENTAGE ERROR :

Let’s assume that we want to find out the percentage error
between the observed value and the true value of the speed of
sound in water.

- Find out the actual value of the speed of sound in water is
1450m/s at 20º C.
- Observe your measurement, it comes out equal to 1425m/s.
- Now, get the difference of measured value and the real value,
by subtracting actual value from the measured value by using the
above formula already mentioned.
- 1450-1425 = 25m/s
- 25m/s is the required absolute error. To find out the
percentage error you need to divide the required difference by
the actual value.
- 25/1450 = 0.017
- Now, at last as per the formula you have to multiply the
required digit with the 100% to get the percentage error.
- 0.017 × 100 = 1.7 %, which is also known as a relative error.

The error percent measures how many percent the observed value
is different from the true value. The smaller is the error value,
the more close and accurate the measured value is compared to the
actual value. The greater is the error value, the less close or
accurate is the measured value is compared to the actual value.

#### EXAMPLE:- What is the error percentage when the real value is
150 and the measured value is 90?

150-90/150 * 100 = 60/150 * 100 = 40%

## HOW TO USE PERCENTAGE ERROR CALCULATOR?

You can use the percent error calculator formula to find out the
error with the help of the calculator. The user just has to enter
the measured value and the actual value and then click the
“calculate” button. Then, automatically the percent error
calculation will be done and hence the value has been shown to
you.

## PERCENT DEVIATION CALCULATOR

What does the percent deviation mean?... Percent deviation
generally refers to a number that has been calculated to check out
the accuracy of during some kind of experiment that is somehow
being compared to the theoretically expected results.

Percent
deviation is calculated by:

- Subtracting the theoretically expected results from the actual
or the real data.
- Then divide it with theoretically expected results.
- And then multiply it by 100.

Now, if we get a negative percent deviation than the measured
number is less than the theoretical value. And, if we get the
positive percent deviation then the measured number is higher. We
can easily find out the percent deviation with the help of the
percent deviation calculator.

## SOME TERMS SIMILAR TO PERCENT ERROR ARE:

- Percent or relative
- Margin
- Standard

We provide you a short explanation regarding these similar
errors so that you don’t get confused and mix up with them.

- STANDARD ERROR = Standard error is the error or the value that
is calculated for the set of data. It is a term used in
statistics that gives the accuracy in which a small part
represents the whole.
- MARGIN OF ERROR = Margin error is generally calculated by
multiplying the standard error with the z-score with a certain
confidence level.

## DIFFERENCE BETWEEN THE ABSOLUTE AND THE RELATIVE ERROR

Absolute error is also known as the approximation error, the
absolute error is generally found out by subtracting the measured
value from the actual value. The value thus observed is known as
an absolute value. You can use the **absolute error calculator** and
the **relative error calculator** to find out both the errors.