A Percentage Increase Calculator is a tool used to calculate the percentage increase of a given number.

It is calculated by subtracting the original number from the new number, dividing the result by the original number, and then multiplying it by 100.

The formula for calculating a percentage increase is:

(New Number - Original Number) / Original Number x 100.

For example, if you have an original number of 10 and a new number of 15, you would subtract 10 from 15 to get 5. Then divide 5 by 10 to get 0.5. Finally, multiply 0.5 by 100 to get 50%. This means that there was a 50% increase from 10 to 15.