Percentage change calculator
Enter a starting value and an ending value to get the percentage change — positive for growth, negative for decline. Track stock moves, salary raises, website traffic swings, and exam score improvements.
How to calculate percentage change
1. Enter the original (old) value.
2. Enter the new value.
3. Read the percent change — positive means increase, negative means decrease.
4. Swap values mentally to see change in the opposite direction.
Percent change examples
Price increase
A product rose from $40 to $52. Change: ((52 − 40) ÷ 40) × 100 = +30%.
Traffic drop
Monthly visits fell from 12,000 to 9,000. Change: ((9000 − 12000) ÷ 12000) × 100 = −25%.
Salary raise
Pay went from $55,000 to $60,500. Change: ((60500 − 55000) ÷ 55000) × 100 ≈ +10%.
When to use percentage change
• When you report KPI growth in dashboards or slide decks.
• When you compare before/after prices during sales analysis.
• When you evaluate investment or portfolio performance over a period.
Relative change vs absolute change
Absolute change is New − Old (dollars, users, points). Relative change expresses that difference as a fraction of the starting point. A site gaining 100 users from a base of 200 (+50%) is a very different story than gaining 100 from 1,000,000 (+0.01%) — relative change captures that context.
Frequently asked questions
What is the percentage change formula?
((New − Old) ÷ Old) × 100. The old value is always the denominator.
Why is going from 100 to 75 not the same as 75 to 100?
Percent change is asymmetric. 100→75 is −25%; 75→100 is +33.33% because the baseline changed.
Can the result exceed 100%?
Yes. An increase from 10 to 30 is +200%. Large relative growth produces percentages above 100%.
What if the old value is negative?
The math still runs, but interpretation is tricky — discuss absolute values in financial contexts.
Is this the same as percentage points?
No. Moving from 10% to 15% interest is a 5 percentage point increase, but a 50% relative increase.