Percentage Change Calculator
Find the percentage change from one value to another. Enter the original and new values and the calculator tells you the exact percentage increase or decrease, the absolute difference, and the ratio between them.
Positive = increase, negative = decrease from the original value
- 1
Absolute change (New − Old)
100 − 80 = 20 - 2
Divide by |Old|
20 ÷ 80 = 0.25Using the absolute value of the original keeps the sign correct even for negative starting values. - 3
Percentage change
(20 ÷ 80) × 100 = 25
How does this calculator work?
Percentage Change = (New − Old) ÷ |Old| × 100. A positive result means the value increased relative to the original; a negative result means it decreased. Enter the starting and ending values above to get the exact percentage change and absolute difference instantly.
Formula
How this is calculated
Percentage change measures how much a quantity has grown or shrunk relative to its original value. The formula divides the absolute difference (New − Old) by the absolute value of the original, then multiplies by 100 to express the result as a percentage. A positive result is an increase; a negative result is a decrease.
The key distinction from percentage difference is direction: percentage change always compares to the starting (original) value in the denominator, so it tells you how large the shift is relative to where you started. If the original value is negative, the calculation still works correctly because the denominator uses the absolute value of the original.
One important limitation: percentage change is undefined when the original value is zero, because division by zero is not meaningful. In that case, you can only report the absolute change.
Frequently asked questions
Percentage change is the relative change from an original value to a new value, expressed as a percentage of the original. It equals (New − Old) ÷ |Old| × 100.
Percentage change is directional — it compares to a specific original (starting) value. Percentage difference is symmetric — it compares two values to their average, so the order does not matter.
Yes. If the new value is more than double the original, the percentage change exceeds 100%. For example, going from 50 to 150 is a 200% increase.
Also known as
TG we-Calculate Editorial Team. (2026). Percentage Change Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/percentage-change-calculator
TG we-Calculate Editorial Team. "Percentage Change Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/percentage-change-calculator.
TG we-Calculate Editorial Team, "Percentage Change Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/percentage-change-calculator
@misc{wecalculate_percentage_change_calculator, title = {Percentage Change Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/percentage-change-calculator}}, year = {2026}, note = {TG we-Calculate} }
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