How it works
change = (new − old) ÷ old × 100positive = increase · negative = decrease
- old
- the starting value
- new
- the ending value
- change
- the percent it went up or down
An increase then the same percentage decrease does not return you to the start, because each percent is taken from a different base.
Frequently asked questions
What is the percentage change from 40 to 50?
A 25% increase.
How do I calculate percentage decrease?
Use the same formula; a smaller new value gives a negative result. From 50 to 40 is a 20% decrease.
Why is a 25% rise not cancelled by a 25% fall?
Because the fall is taken from the higher new value, so it removes more than the rise added.
What is the percent increase from 100 to 150?
A 50% increase.