Percent Deviation Calculator

This tool computes the percent deviation of a sequence of data from a standard value.

To use the calculator enter the

  • sequence of values, each separated by a comma
  • standard value

	

			

		

						

				

				

                

			

			
						

		

		






Background





Formula





xMean = (1/n)*(x1 + x2 + … + xn)





D% = ((xMean – xStd)/xStd)*100





Calculation Examples





For a set of values 1, 5, 9 and a standard value of 7, the percent deviation can be calculated as follows:





    

  • Find the mean value. In this case it is (1+5+9)/3 = 5.
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  • The percent deviation is ((5-7)/7)*100 = -28.57%
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In the event that the sequence consists of only one value, say 12 then the mean value is also 12. The percent deviation is ((12-7)/7)*100 = 71.43%