Answer: The percentage change from $100 to $80 is -20.00 %.
The above answer is not currency dependent, whether you use US dollars, euros or other currencies.
How Can I Calculate percent change from $80 to $100
Here is a quick calculation to find the percentage increase or decrease in an item price of $80 and the original price of $100. The procedure and video is as follows:
Step1
The need to be known
In the case above, the original price of the product is $100 and the current price is $80.
Step2
Calculate the price difference
The current price of the product is lower than the original price, product at $20.00
Step3
ratio changed
The difference is divided by the original price to give the difference as a percentage of the original price. Note that it is not divided by the current price, so the result is 20.00 / 100 = 0.20.
Step4
percentage changed
The conversion of a ratio of change to a percentage of change is a simple process of multiplying the ratio by 100, so the result will be 0.20 * 100 = 20.00%.