Percentage Increase/Decrease
Work out the percentage change between two values, or increase or decrease a number by a percentage.
Runs in your browser — nothing is uploadedEnter values
Calculate
Result
- Difference
- 25
- New ÷ original
- 1.5×
How it's calculated
% change = (New − Original) ÷ |Original| × 100
= (75 − 50) ÷ 50 × 100 = 50%
About Percentage Increase/Decrease
Percentage change shows how much a value has grown or fallen relative to where it started. It is the standard way to compare prices, salaries, sales, website traffic, population and investment performance over time.
This tool calculates the percentage increase or decrease between two values, and can also apply a percentage change to a number — for example, a 15% raise on a salary or a 20% price cut. The difference and formula are shown with every result.
When to use it
- Comparing this month’s sales or revenue with last month.
- Calculating a salary increase or price rise.
- Measuring changes in website traffic or followers.
- Checking inflation or price changes between two years.
Tips for better results
- Always divide by the original (old) value, not the new one.
- A 50% fall followed by a 50% rise does not return to the start — it ends 25% lower.
- Use percentage points, not percent, when comparing two percentages (e.g. 5% → 7% is +2 points).
How to use the Percentage Increase/Decrease
- Pick "% change" or "increase / decrease by %".
- Enter your values.
- See the change, the difference and the formula.
Frequently asked questions
How is percentage change calculated?
Percentage change = (new − original) ÷ |original| × 100. Going from 50 to 75 is a 50% increase.
Why can't I calculate a change from 0?
Any increase from zero is infinitely large as a percentage, so the change from 0 is undefined. Compare the absolute difference instead.
What is the difference between percent and percentage points?
If an interest rate moves from 5% to 7%, it rose by 2 percentage points, but by 40% in relative terms (2 ÷ 5 × 100). Percentage points describe the absolute gap between two percentages.
How do I reverse a percentage increase?
Divide the new value by (1 + the increase). For example, a price of 115 after a 15% rise was originally 115 ÷ 1.15 = 100.