百分比变化计算器
计算两个值之间的百分比变化幅度。
Percentage Change (%)
25.0000
Percentage Change (%) vs Old Value
公式
How to Calculate Percentage Change
Formula
% Change = [(New - Old) / Old
Percentage change measures the relative difference between two values. A positive result indicates an increase; negative indicates a decrease. Using the absolute value of the old value in the denominator handles cases where the old value is negative.
计算示例
A price changes from $80 to $100.
- 01Change = 100 - 80 = 20
- 02% Change = (20 / 80) * 100 = 25%
- 03Ratio = 100 / 80 = 1.25
- 04The price increased by 25%
常见问题
Is percentage change symmetric?
No. Going from 80 to 100 is a 25% increase, but 100 to 80 is a 20% decrease. The asymmetry arises because the base (denominator) changes. For symmetric comparison, use the percentage difference formula with the average as the base.
What if the old value is zero?
Percentage change is undefined when the old value is zero because you cannot divide by zero. In such cases, report the absolute change instead or use a small baseline value.
How is percentage change different from percentage difference?
Percentage change measures change from a specific reference (old to new). Percentage difference compares two values symmetrically using their average as the base: 2*|A-B|/(|A|+|B|)*100.
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