percentage change calculator
enter an old value and a new one to see how much it moved in percent. a plus sign means it grew, a minus sign means it fell.
runs on your device · free · no sign-up
loading tool…
how to percentage change calculator
- pick a mode: x% of y, x is what % of y, % change, % increase or % decrease.
- type the two numbers. the result and the formula update as you type.
- tick compare two scenarios to test a second pair of numbers next to the first, such as two discounts.
- press copy share link to send the exact inputs to someone else.
the formula is (new − old) ÷ |old| × 100. the example loaded here compares 250 to 300 against 300 to 250: the first is +20%, the second only −16.7%, because the starting value is different. the comparison box is on so you can see that asymmetry right away.
percent change is the right tool for prices, traffic, revenue and test scores. for two percentages (a rate going from 4% to 6%) report the difference in percentage points as well, since "a 50% increase" and "2 points higher" describe the same move very differently.
more ways to percentage calculator
frequently asked questions
what if the old value is zero?
the percent change is undefined, because you cannot divide by zero. the tool shows a message instead of a number. use the absolute difference in that case.
what does a negative result mean?
it is a decrease. going from 80 to 60 gives −25%. the result box also labels it as an increase or a decrease.
how do i calculate the change between three or more values?
calculate each step on its own, old to new, then new to the one after. do not average the percentages; chain them by multiplying the growth factors if you need the total.