Percentage Increase Calculator

Calculate percentage increase from original to new value. Find the percent change between two numbers.

This calculator subtracts the Original Value from the New Value to get the raw Increase, then divides that Increase by the Original Value and multiplies by 100 to express it as a percentage. Because the percentage is divided by Original Value rather than New Value, the two inputs do not pull in the same direction: raising New Value while Original Value stays fixed pushes both Increase and Percentage Increase up together, but raising Original Value while New Value stays fixed actually pulls Increase down, since a larger starting point leaves less room between it and a fixed ending point. At the default figures of 100 rising to 120, moving New Value has a slightly larger effect on the reported Increase than moving Original Value by the same proportion does, because a percentage nudge moves a field by an amount proportional to its own magnitude — and New Value, being the larger of the two numbers at the defaults, moves by more raw units than Original Value does for the same percentage nudge, a genuine, measurable asymmetry between the two fields rather than something either input's label would suggest on its own. The formula assumes Original Value is not zero, since dividing by zero has no defined result; the engine falls back to reporting a 0% change rather than an error in that specific case, which is worth knowing if you are working with a value that starts at nothing. Nothing in this tool distinguishes a genuine increase from a decrease dressed up as one — enter a New Value smaller than the Original Value and it will still compute a signed negative Increase and negative Percentage Increase without renaming the output or redirecting you elsewhere.