Enter an original and a new value to get the exact percentage increase or decrease, with the direction and absolute change shown.
How percentage change is worked out
Percentage change always compares against the original value: the difference between the two numbers, divided by what you started with. That “divided by the original” step is the part people flip, and it is why a 50% increase followed by a 50% decrease does not return to the start.
How to use it
- Enter the original (from) value.
- Enter the new (to) value.
- Read the percentage change — positive means increase, negative means decrease.
The formula
A worked example
The calculator opens going from 50 to 65. The difference is 15, and 15 ÷ 50 = 0.30, so the result is +30%. Reverse the numbers — 65 down to 50 — and the change is −23.08%, not −30%, because the base changed. That asymmetry is the whole reason to use the calculator rather than intuition. Change any field and every figure updates as you type.