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.
Quick answer: Percentage increase and percentage change use the same formula when the new value is higher than the original value. Percentage change can also describe a decrease, while percentage increase only describes an upward move.
| Measure | Use it when | Baseline |
|---|---|---|
| Percentage increase | The new value is higher | Original value |
| Percentage decrease | The new value is lower | Original value |
| Percentage change | The direction may be up or down | Original value |
| Percentage difference | Neither value is the starting point | Average of both values |
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. Percentage change can carry the negative sign; percentage increase cannot describe a downward move.
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 useful when neither number is the baseline, so it divides by the average of the two values:
Percentage difference = |Value 1 − Value 2| ÷ ((Value 1 + Value 2) ÷ 2) × 100For 50 and 65, the absolute difference is 15 and the average is 57.5. The percentage difference is about 26.09%. If 50 was specifically the original value, the percentage increase would instead be 30%.
Do not switch between the formulas without deciding which relationship your data represents.
Which term should you use?
- Use percentage increase when a value rose from a known starting point.
- Use percentage decrease when it fell from a known starting point.
- Use percentage change when one formula must cover either direction.
- Use percentage difference to compare two values with no meaningful order.
For a change over time, the earlier value is normally the original value. For two measurements taken under equal conditions, percentage difference may be the clearer choice.
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 values with the Percentage Increase Calculator
If both values are already percentages, also check percentage points versus percent increase.