Percent Change Calculator
See exactly how much a number went up or down — in percent.
Inputs
Result
Percent change
25.00%
increase
Visual breakdown
From80
To100
Formula
change = (To − From) / |From| × 100
Example
From 80 to 100 = +25%. From 100 to 80 = −20%.
Frequently asked
Why is dividing by zero undefined?
If the starting value is zero, percent change isn't meaningful — any non-zero new value is an infinite increase.
Does it work with negative numbers?
Yes, but interpret with care. We use the absolute value of the starting number to keep the sign of the change intuitive.
Can I use this for stock returns?
Yes — it's the same formula. For multi-period returns, use the Interest Calculator instead.