How to Calculate Percent Error [+3 Tools]

Percent error in a selection of knowledge is the adaptation between the precise and approximate values when compared to the unique price. This p.c error is expressed as a proportion and therefore multiplied through 100.

You can categorical p.c error as absolute error or relative error. Errors would possibly happen on account of precision error in a system, computing error, size error, or environmental stipulations. 

Percent mistakes assist us to resolve how vital our mistakes are right through any research. More minor p.c mistakes imply that we’re shut to the unique price, whilst extra really extensive p.c mistakes imply a substantial discrepancy between the true price and approximate price. 

For instance, a 2% error would imply that we’re very shut to the unique price, whilst a 56% error would imply a large distinction between the true and approximate price. 

Errors whilst measuring are pervasive as a result of palms would possibly shake right through measurements, tools could also be inaccurate, subject matter might not be exact, and so forth. 

Percent error calculation

To calculate p.c error, you should have two to be had values. One is the precise price, and the second is the approximate price. Subtract each those values after which divide them with the unique price. Since p.c error is expressed within the type of p.c, multiply the quantity thus gained through 100. In different phrases, p.c error is relative error multiplied through 100. 

Percentage Error = [(Actual Value – Expected Value) / Expected Value] × 100

Components of the method

Actual price: The exact price signifies the numerical price of explicit reading. The exact price must had been recorded whilst taking the reading, however due to some mistakes, shall we now not report this price. It is a commonplace price this is preferrred for wearing out calculations. 

Expected price: The anticipated price signifies the reading recorded whilst experimenting. It isn’t an identical to the true price usually on account of error. Errors could also be due to default within the system, error whilst taking the reading, or environmental elements similar to air or damaged and broken tools. 

Some Examples 

Example 1

A boy was once measuring the world of a triangle, and in accordance to him, the reading was once 462 sq. cm. However, the unique house of the sq. is 465 sq. cm. Calculate the p.c error.


Value of measured house = 462 sq. cm

Value of tangible house = 465 sq. cm


Difference of tangible price – measured price: 465-462 = 3

So, 3 is the size error.

Divide the mistake through the true price – 3/465 = 0.00645

Multiplying the worth bought through 100 – 0.00645 X 100 = 0.64%.

Therefore, the p.c error in calculating the world of a triangle is 0.64%

Example 2

Suppose you had been making plans a birthday party and an estimated 20 other folks can be attending the birthday party whilst handiest 18 other folks controlled to come. Calculate the p.c error for your estimation.


The authentic choice of other folks anticipated = 20

People who got here = 18


Difference of tangible price – ultimate price = 20 – 18 = 2

So, 2 is the mistake over right here.

Divide the mistake through the true price – 2/20 = 0.1

Multiplying the worth through 100 – 0.1 X 100 = 10%

Therefore, the p.c error in estimating the choice of visitors is 10%.

Example 3 

Suppose you carried out an experiment to measure the boiling level of water, and whilst experimenting, you discovered the effects to be 102°C. The exact freezing level of water is 100°C.


The exact boiling level of water = 100° C

The recorded boiling level of water = 102°C


The distinction between the true price and calculated price = 100 -102 = 2°C (Percent error can by no means be unfavorable, so we stay it sure handiest).

So, 2 is the mistake over right here.

Divide the mistake through the true price – 2/100 = 0.02

Multiplying the worth bought through 100 – 0.02 X 100 = 2%

Therefore, the p.c error in measuring the boiling level of water is two%. 

Real-world situations the place p.c error is essential

  • Percent error performs a vital position in serving to you to resolve whether or not a selected process you finished was once up to the mark or now not. It is helping you in mentioning your errors. 
  • Percent error could also be useful in laboratory procedures and big industries and not using a scope for the slightest error. 
  • Percent error additionally reveals its utilization when now we have a bulk order to entire, and there can’t be any scope of error in its finishing touch. 
  • In science laboratories, the usage of proportion error is significant.

Percent Error vs. Absolute Error

An absolute error in a size is the adaptation between the true and calculated values. The unit of elementary error is equal to the preliminary price. 


Suppose you had been making plans to acquire 2 kg mangoes whilst the shopkeeper measured 1.98 kg for you. The absolute error, on this case, will likely be 2 – 1.98 = 0.02.

On the opposite hand, p.c error is calculated through dividing absolute error through the unique price after which multiplying the solution bought through 100. Percent error is a unitless amount.

In the above instance, the absolute error is 0.02.

Now to calculate the p.c error, we can divide it through 20. 

0.02/20 = 0.001

The p.c error, on this case, is thus 0.001 X 100 = 0.1%.

Percent error vs. Relative error

The relative error in any calculation is absolutely the error divided through the true price. This implies that p.c error is the adaptation between the actual price and the seen price divided through the true price. 


The climate forecast anticipated the temperature nowadays to be 38°C. However, it rose to 42°C.

First we discover the adaptation between the 2 numbers, i.e., the anticipated price and the true price.

42° – 38° = 4°C

Now for calculating relative error, we divide this quantity through the true quantity, i.e., 38°C 

4/38 = 0.1052

On the opposite hand, the p.c error is a relative error multiplied through 100.

In the above instance, the p.c error will likely be 0.1052 X 100 = 10.52%.

Now, you may to find it lovely simple to calculate p.c error, relative error, or absolute error.

You could make p.c error calculations more uncomplicated through taking the assistance of a number of on-line p.c error calculators. Now, you received’t have to surprise how to calculate p.c error as a result of those calculators can do it occupied with you.

Error calculation gear

#1. Calculator Soup 

The Calculator Soup is helping you to calculate the proportion error between the experimental price and the true price. All you’ve gotten to do is enter the values and look ahead to the effects. The calculator plays the entire calculations on its own and will provide you with correct effects. 

Calculator Soup

The web page presentations two other columns by which you enter the worth of numbers you wish to have to calculate p.c error for and let the calculator do the remainder of the magic. 

#2. Calculator.internet has two columns the place you input the true and estimated values and let the calculator do the remainder of the calculations. This is useful when there are many samples of knowledge you wish to have to calculate, and also you don’t have the time to calculate the p.c error in each and every case manually. The calculator eases the method and will provide you with the solution instantly with out a lot lengthen.

Percent mistakes are inevitable. You can handiest decrease their price, however there received’t be any occurrence when the reading of p.c error is going to 0. It will also be roughly 0 however can by no means be a precise 0. 

#3. Good Calculators

Many on-line calculators would possibly allow you to in fixing your proportion error issues. Of those, one of the crucial only is the Good Calculators. In this calculator, you simply enter the estimated and authentic price, and it’s going to mechanically give the effects.

It saves you from the trouble of appearing in depth calculations and protects your time. You can temporarily clear up complete calculations inside seconds and prevent numerous time. 

percent error calculator

Thus, a calculator is perfect for the calculation of p.c error in case you have in depth knowledge to be had to hand however are operating in need of time.


Errors in calculations can utterly spoil any challenge or analysis. This is the place you’ll be able to take the assistance of on-line p.c error calculators to get the paintings accomplished extra successfully and with none human mistakes.

If you might be into finance, it’s possible you’ll have a look at a few of these benefit proportion calculators.

Related Articles

Leave a Reply

Your email address will not be published.

Back to top button