Percentage Calculator                 see examples

         
         
%  of     =  
Answer

           


 

(Enter values into the blue boxes. Select a different box to be the answer box if needed.)
Answers are rounded to 7 decimal places.



Percentage Calculator in Common Phrases:                 see examples


percent of is   


is what percent of ?    %


What percent of is ?    %


is percent of what?   


(Enter values into the blue boxes. Answers will appear in the black boxes.)
Answers are rounded to 7 decimal places.




Percent Calculator                 see examples

Percent to Fraction to Decimal
Decimal to Fraction to Percent


Percent      Fraction   Decimal
 %     =    
    =    


Answers are rounded to 7 decimal places.




Add or Subtract a Percentage                 see examples

Calculate: tips, sales price, percent off, discounted price, price with sales tax, etc.




Start Value  % of Start Value End Value
      %  =  
 



(Enter values into the blue boxes. Answer will appear in the black box.)
Answers are rounded to 7 decimal places.




Percent Change                 see examples

Percent Increase
Percent Decrease

Use when comparing an old value to a new value or when comparing a start value to an end value.



Start Value End Value Percent Change
                     %


A positive answer for percent change represents a percent increase.
A negative answer for percent change represents a percent decrease.


Percent Change  =  
End Value - Start Valueabs(Start Value)
   x 100%
(where abs = absolute value)

(Enter values into the blue boxes. Answer will appear in the black box.)
Answers are rounded to 7 decimal places.




Percent Error                 see examples

Use when comparing a theoretical (known) value to an experimental (measured) value.



Theoretical Value Experimental Value Percent Error
                     %


Percent Error  =  
abs(Experimental Value - Theoretical Value)abs(Theoretical Value)
   x 100%
(where abs = absolute value)

(Enter values into the blue boxes. Answer will appear in the black box.)
Answers are rounded to 7 decimal places.





Percent Difference                 see examples

Use when comparing two values where neither value is considered a start value or a reference value.



One Value Another Value Percent Difference
                     %


Note: There is no standard equation for percent difference for all circumstances. The equation used here divides the difference between the two values by the average of the two values (see equation below). Some cases may require you to divide by the minimum of the two values or the maximum of the two values, etc. Please check that the equation used here fits your circumstance.


Equation used:
Percent Difference  =  
abs(One Value - Another Value)abs((One Value + Another Value)/2)
   x 100%
(where abs = absolute value)

(Enter values into the blue boxes. Answer will appear in the black box.)
Answers are rounded to 7 decimal places.





Definitions:


Percent:

Percent means per 100 or parts per 100. It can be used to describe a portion of a whole or part of a whole. It comes from per cent which is short for per centum which means per hundred.

The percent sign is: %

1 percent (1%) = 1 part per 100 = 1/100 = 0.01   (a portion less than a whole)
100 percent (100%) = 100 parts per 100 = 100/100 = 1   (a portion equal to a whole)
110 percent (110%) = 110 parts per 100 = 110/100 = 1.1   (a portion greater than a whole)


Percentage:

An amount per 100 that refers to a portion of a whole (in a general way) typically without using a specific number.


Percent vs. Percentage

The word percent is typically used with a number (example: 10 percent) while percentage is typically not used with a number (example: what percentage of the marbles are red?). An exception is percentage points (example: 2 percentage points).


Percentage Calculator:

Calculator or tool that uses the percentage formula to solve for a desired value in that formula. The percentage formula contains three variables. If any two of the variables are known, the third variable can be calculated.


Percentage Formula:

Formula used to solve percentage problems that relates two ratios where one of the ratios is a part or portion per 100 and the other ratio is a part or portion per a whole.

Where:
A% of B is C                                     as in:  10% of 90 is 9      where A=10, B=90, C=9

The percentage formula is:
A/100 x B = C                                   as in:  10/100 x 90 = 9

Rearranging:
A100 = CB                                               as in:  10100 = 990

The percentage formula is sometimes expressed as:
percent100 = is(part)of(whole)                           as in:  10100 = 990

Solving for each of the variables yields:
A = (C / B) x 100                              as in:  A = (9 / 90) x 100 = 10
B = C / (A / 100)                               as in:  B = 9 / (10 / 100) = 90
C = (A / 100) x B                              as in:  C = (10 / 100) x 90 = 9

Note: A% = A/100 because % means per 100


How are percentages used?

  • store discounts: 25 percent off sale
  • sales tax is typically a percentage of purchase price: 8% sales tax
  • interest rates for savings accounts are typically shown as an annual percentage rate (apr): 1.5% apr
  • interest rates charged by credit card companies and mortgage companies are shown as an annual percentage rate.
  • interest rate changes: interest rates rose one percentage point from 4.5% to 5.5%
  • statistics: the margin of error is plus or minus four percentage points
  • credit card rewards: 2% cash back for certain purchases
  • news: approval ratings, employment rate, and surveys can be expressed using percentages
  • laptops, tablets, and cell phones usually have a battery charge percentage indicator
  • weather forecast: 20 percent chance of rain
  • probability: the chance to win a prize is 1 in 10 or 10 percent
  • humidity: the humidity level is 65%

Percentages can be used to make the relationship between a portion and a whole easier to understand.

Anytime you need to solve a percentage problem, the percentage calculator is here to help.