Percentage change is the broad term for movement from an original value to a new value. Percentage increase is the positive version of that calculation.
They use the same basic formula
Percentage change = ((New − Original) ÷ Original) × 100When the result is positive, it is a percentage increase. When the result is negative, it is a percentage decrease.
A value moving from 160 to 200 has a change of 40. Dividing 40 by 160 gives 0.25, so the result is a 25% increase.
A value moving from 200 to 160 gives −20%. In plain language, that is a 20% decrease.
The order changes the result
The original value must describe the earlier or baseline value. Reversing 80 and 100 does not simply reverse the sign:
- 80 to 100 is a 25% increase.
- 100 to 80 is a 20% decrease.
The two percentages differ because each uses a different starting value. This is explored further in why equal increases and decreases do not cancel.
Percentage change is not percentage difference
Percentage change has a clear original value. Percentage difference is often used when neither number is the baseline, so it divides by the average of the two values. Do not switch between the formulas without deciding which relationship your data represents.
Use direct wording
Describe a positive result as “increased by 25%.” Describe a negative result as “decreased by 20%.” If you write “changed by −20%,” readers must interpret the sign themselves.
Compare an original and new value
If both values are already percentages, also check percentage points versus percent increase.