Percentage Rate Change Calculator
Determine the precise percentage increase or decrease between two values.
The percentage change is:
Understanding Percentage Increase and Decrease
Calculating the percentage rate of change is a fundamental mathematical process used across various fields, including finance, statistics, and science. It measures the relative difference between an original value and a new value, expressed as a fraction of 100.
The Percentage Change Formula
To find the percentage increase or decrease manually, use the following universal formula:
((Final Value – Initial Value) / |Initial Value|) × 100
How to Calculate It Step-by-Step
- Subtract the initial value from the final value to find the absolute change.
- Divide that absolute change by the original (initial) value.
- Multiply the resulting decimal by 100 to convert it to a percentage.
- Identify the Direction: If the result is positive, it is a percentage increase. If the result is negative, it is a percentage decrease.
Example 1: Percentage Increase
If a website's traffic grows from 1,200 visitors (Initial) to 1,800 visitors (Final):
(1,800 – 1,200) = 600
600 / 1,200 = 0.5
0.5 × 100 = 50% Increase.
If a website's traffic grows from 1,200 visitors (Initial) to 1,800 visitors (Final):
(1,800 – 1,200) = 600
600 / 1,200 = 0.5
0.5 × 100 = 50% Increase.
Example 2: Percentage Decrease
If the weight of a mechanical part is reduced from 250g (Initial) to 215g (Final):
(215 – 250) = -35
-35 / 250 = -0.14
-0.14 × 100 = 14% Decrease.
If the weight of a mechanical part is reduced from 250g (Initial) to 215g (Final):
(215 – 250) = -35
-35 / 250 = -0.14
-0.14 × 100 = 14% Decrease.
Why Use This Calculator?
While the math seems straightforward, errors often occur when dividing by the wrong number (the final instead of the initial) or when dealing with negative starting values. Our calculator automates the logic, ensuring your business reports, scientific data, or personal growth metrics are 100% accurate every time.