Percentage Calculator
A percentage is a number expressed as a fraction of 100, so X% of a value equals (X ÷ 100) × that value. This calculator finds what percent one number is of another, percentage increase or decrease, and reverse percentages, showing the working steps for every result.
Reviewed for accuracy by Daniel Agrici, Founder & Lead Developer · Editorial policy
How do you calculate a percentage?
Percentage = (Part / Whole) x 100
Percentage expresses a number as a fraction of 100. To find X% of Y: Result = (X / 100) x Y. To find what percent X is of Y: Percentage = (X / Y) x 100. To compute percentage change between an original and a new value: Change = ((New - Old) / |Old|) x 100. A positive change is an increase; a negative change is a decrease. These three formulas cover the vast majority of real-world percentage problems, from calculating discounts and tax amounts to comparing wages and interpreting grade scores.
How do you work out percentages step by step?
Example 1: Finding a percentage of a number
Problem:What is 15% of 240?
Solution:Multiply 240 × 0.15 (15 ÷ 100 = 0.15)
Result:240 × 0.15 = 36. So 15% of 240 is 36.
Example 2: Percentage change (increase)
Problem:A product's price rose from $80 to $92. What is the percentage increase?
Solution:Percentage change = ((New − Old) ÷ Old) × 100 = ((92 − 80) ÷ 80) × 100
Result:(12 ÷ 80) × 100 = 15% increase
Example 3: Reverse percentage (find the original)
Problem:After a 20% discount, an item costs $64. What was the original price?
Solution:Original = Discounted Price ÷ (1 − discount rate) = 64 ÷ 0.80
Result:64 ÷ 0.80 = $80 was the original price
What else do people ask about percentages?
How do I find what percentage one number is of another?
To find what percentage X is of Y, divide X by Y and multiply by 100. For example, 45 is what percent of 180? 45 / 180 = 0.25, then 0.25 x 100 = 25%. The formula is Percentage = (Part / Whole) x 100.
How do I calculate percentage change between two numbers?
Percentage change = ((New Value - Old Value) / |Old Value|) x 100. If the result is positive, it is an increase. If the result is negative, it is a decrease.
What is the difference between percentage and percentile?
A percentage is a fraction of 100 used to express a proportion, while a percentile indicates the position of a value within a distribution.
Why is percentage increase and decrease not symmetrical?
A 50% increase followed by a 50% decrease does not return to the original value because the base changes between the two calculations.
References
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