Can this show a decrease too?
Yes. If the new value is lower than the original value, the result is shown as a decrease.
Compare an original value and a new value to see the exact percentage change.
Use it when comparing an old value with a new value and you need the percent increase or decrease between them.
Questions
Yes. If the new value is lower than the original value, the result is shown as a decrease.
A starting value of zero would make percentage change undefined.
Yes. The calculator also shows the numeric change between the two values.