% of  =  
Answer 
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percent of  is 
is what percent of  ?  % 
What percent of  is  ?  % 
is  percent of what? 
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Percent  Fraction  Decimal  
%  = 

= 
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Calculate: tips, sales price, percent off, discounted price, price with sales tax, etc.
Start Value  % of Start Value  End Value  
% =  
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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.
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Use when comparing a theoretical (known) value to an experimental (measured) value.
Theoretical Value  Experimental Value  Percent Error  
% 
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Answers are rounded to 7 decimal places.
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.
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Answers are rounded to 7 decimal places.
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)
An amount per 100 that refers to a portion of a whole (in a general way) typically without using a specific number.
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).
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.
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
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.