Percentage Change Calculator
(New − Original) ÷ |Original| × 100(100 − 80) ÷ 80 × 100 = 25%
Free online tool
Percentage Change Calculator
Measure how far a value moved from its original amount and identify the result as an increase or decrease.
Instant calculation
Percentage change from X to Y
Measure an increase or decrease between two values.
Your result
Calculation
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The formula
How this calculation works
Find the numerical change, divide it by the absolute original value, and multiply by 100. Positive results are increases; negative results are decreases.
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Worked examples
Each example follows the same formula used by the calculator above.
What is the change from 80 to 100?
(100 − 80) ÷ 80 × 100 = 25%Answer: 25% increaseWhat is the change from 100 to 80?
(80 − 100) ÷ 100 × 100 = −20%Answer: 20% decreaseWhat is the change from 50 to 50?
(50 − 50) ÷ 50 × 100 = 0%Answer: no changeCommon questions
Questions about this calculation
What is the difference between percentage change and percentage difference?
Percentage change compares a new value with a specific original value. Percentage difference compares two values without treating either one as the starting point.
Why is percentage change undefined when the original value is zero?
The original value is the denominator in the formula. Dividing by zero is undefined, so a finite percentage change cannot be calculated.
How are negative original values handled?
This calculator divides by the absolute original value so the sign of the result clearly describes the direction of movement. Interpret negative-value changes in context.
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