Percentage Change Calculator
Calculate percentage increase or decrease between any two values
Percentage Change Calculator
What is X% of Y?
% of—
Frequently Asked Questions
How do I calculate percentage change?
Percentage change = ((New Value - Old Value) / Old Value) × 100. Positive means increase; negative means decrease.
What is the difference between percentage change and percentage point change?
Percentage change is relative (e.g., 50% to 60% is a 20% increase). Percentage point change is absolute (50% to 60% is a 10 percentage point increase).
How do I reverse a percentage increase?
If a value increased by X%, divide by (1 + X/100) to find the original. Example: a 25% increase to 125 → original = 125/1.25 = 100.
About this calculator
Percentage change tells you how much a value has grown or shrunk relative to where it started. Enter an original and a new value and the calculator gives the percentage change, labelled as an increase or a decrease, along with the absolute difference.
A second block finds what a given percentage of a number is, which is handy for working out the new value after a planned rise or cut. Use it for prices, salaries, marks, weight, sales and traffic.
How to use it
- Enter the Original Value and the New Value.
- Press Calculate.
- Read the percentage and whether it is an increase or a decrease.
Formula
Percentage change = (New − Old) ÷ |Old| × 100. A positive result is an increase and a negative one a decrease. The original value cannot be zero, because the change is measured against it.
Worked example
Examples
| 80 to 100 | 25% increase, absolute change 20 |
| 100 to 80 | 20% decrease |
| ₹40,000 to ₹46,000 salary | 15% increase |
| 5 kg to 4.5 kg | 10% decrease |
Tips and common mistakes
- Always divide by the starting value, not the new one.
- A 50% fall needs a 100% rise to recover.
- For repeated changes, multiply the factors: +10% then +10% is +21%, not +20%.
- When the original is zero, percentage change is undefined. Report the absolute change instead.
- Quote the base year or month when you publish a percentage change.
Frequently asked questions
How do I calculate percentage change?
Subtract the old value from the new, divide by the old value and multiply by 100.
Why is a 25% rise not undone by a 25% fall?
Because the second change is measured on a larger base.
What if the percentage change is negative?
It is a decrease.
Can the change be over 100%?
Yes. Doubling is a 100% increase and tripling is 200%.
What is the difference from percentage difference?
Percentage change has a direction and a starting point. Percentage difference compares two values symmetrically.
How do I find the new value from a percentage?
Multiply the original by one plus the rate.