Formula
The starting value is the base:
Percent change = (new value − starting value) / starting value
A negative result is a decrease. Percentage difference uses the average of the two numbers instead.
Assumptions
- The starting value is not zero.
- The sign shows the direction of the change.
Worked example
A change from 80 to 100 is 25.00%.
Input definitions
- Starting value
- The base of the percent. It cannot be zero.
- New value
- The later number.
Limitations
Results are rounded for display. This is a classroom calculation, not a measurement from a lab or a financial filing.
Questions
How is this different from percentage difference?
Change divides by the starting value. Difference divides by the average of the two absolute values.
Does the general percentage page do this too?
One of its three modes does. This page answers only the change and also shows the amount added or removed.