About percentage change
This calculator finds the percentage change from one number to another — an increase or decrease — along with the absolute difference. Enter the old and new values and it computes ((new − old) ÷ |old|) × 100. It runs in your browser.
How Percentage Change works
How to use it
- Enter the original (from) value.
- Enter the new (to) value.
- Read the percentage change.
How it works
The change is the difference divided by the absolute starting value, as a percentage. A positive result is an increase, a negative one is a decrease.
Common uses
- Calculate a percentage increase
- Calculate a percentage decrease
- Compare prices over time
- Measure growth or decline
- Work out a salary change
- Compare before and after
- Analyse data changes
- Help with maths homework
Frequently asked questions
How do I calculate percentage change?
((new − old) ÷ |old|) × 100.
What does a negative result mean?
A decrease from the old value to the new value.
What if the old value is zero?
Percentage change from zero is undefined; the difference is shown instead.
Is my input uploaded?
No — it calculates in your browser.
Is this the same as percentage difference?
No — change is directional (old→new); difference compares two values symmetrically.
Can values be negative?
Yes — it uses the absolute starting value as the base.
Is it free?
Yes — completely free with no sign-up.