# Percentage Decrease Calculator

## How to Calculate Percentage Decrease

Percentage decrease is found by dividing the decrease by the starting number, then multiplying that result by 100%.
$\text{Percent Change} = \frac{\text{Decrease}}{\text{First Value}} \times 100\%$
Note: the percent decrease measures FROM the first value. A decrease from 50 of 25 is a change of 50% (25 is the difference between the two numbers, and 25 is 50% of 50)). If that decease were looked at the other way around, it would be a different percentage change (25 increase by 25 to 50 is an increase of 100%).

## Example

Decrease from 50 by 25:
$\frac{25}{50} \times 100\% = 0.5 \times 100\% = 50%$
Decrease from 75 by 25:
$\frac{25}{75} \times 100\% = 0.333 \times 100\% = 33.3%$
Decrease from 0.0443 by 0.0001
$\frac{0.0001}{0.0443} \times 100\% = 0.002257\times 100\% = 0.2257%$

## What is a percentage?

A percentage is a number expressed as a fraction of 100.
If a number is 100% (100 percent), then it is a “whole” – the same as one.
If a number is 50%, then it is a half – the same as 0.5 or 1/2.
If a number is 400%, then it is 4 times, the same as 4.