Additional Information
Remember that percentage changes are always based on the original value.
As an example. Consider an article costing 200 pounds. This costprice is increased by 10% to make the sellingprice 200 + 20 = 220 pounds.
Now, someone who knows that 10% was put ON the costprice, and can see the sellingprice is 220 pounds, wishes to know what the costprice was.
They might think like this: 10% of 220 = 22. So the costprice must have been 220  22 = 198 pounds. Which we know is wrong!
This is a very common problem with goods which carry a tax.
Putting the percentage in the Percentage change and the sellingprice in as the Value after increase will reveal the costprice as the Original value

 Fractions & Percentages
A common fraction is written as a number over another number with a line drawn between them. The top number is called the numerator and the bottom is the denominator. In this calculator it is possible to change a common fraction into its equivalent as a percentage. Just put the numerator (=top number) in as Amount of change and the denominator (=bottom number) as Original value and press Calculate It and the value in Percentage change will be the equivalent of that common fraction. Caution In this calculator it is not possible to enter zero or negative numbers.
However it is possible, in some circumstances, that negative numbers may appear as one of the solution values. Whether these solutions are valid will depend upon the context in which the problem arises.
