Here we look at how to calculate a percentage decrease – this is where your initial value (x) has reduced to a lower value (y).

## Percentage Decrease Calculator

# How to work out percentage decrease - the forumula

To work out a percentage decrease you need to calculate the decrease, divide the decrease by the original value and then multiply that amount by 100.

With the figures above you would do the following:100 - 80 = 20 Then: 20 / 100 = 0.2 Then: 0.2 x 100 = 20 - showing a 20% decrease in the amount.