百分比变化率计算器
计算两个值之间的百分比变化率。
Calculating Percentage Increase and Decrease
概述
Percentage change measures how much a value has grown or shrunk relative to its starting point — essential for tracking prices, metrics, and results. This calculator finds the percentage increase or decrease between two numbers instantly in your browser.
使用步骤
- 1
Enter the original value
The starting (old) number.
- 2
Enter the new value
The number you are comparing against the original.
- 3
Read the percentage change
A positive result is an increase, negative is a decrease.
工作原理
Percentage change = ((new value − old value) ÷ old value) × 100. A positive result is an increase, a negative one a decrease. The key is that the change is always measured against the original (old) value, which is why a rise from 50 to 100 is a 100% increase, but a fall from 100 to 50 is only a 50% decrease — the base is different each way.
什么时候用
Tracking a price rise or drop. Measuring growth in followers, sales, or traffic. Comparing this period's figure against last period's.
常见问题
Because percentage change is measured against the starting value. 50 to 100 is +100% (base 50), but 100 to 50 is −50% (base 100).