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- Percentage change calculator
Free tool · runs in your browser
Percentage change calculator, with the chart to post.
Increase, decrease, percent difference and CAGR, with the formula filled in and a before and after card.
Start from a real chart
The headline number is worked out from your two values. The bars share one scale that starts at zero.
The three formulas
Percent change
(new − start) ÷ start × 100
Use it when one number came after the other: last year to this year, before and after a launch. A negative answer is a decrease.
Percent difference
|a − b| ÷ ((a + b) ÷ 2) × 100
Use it when neither number is the starting point, like two shops or two models. It gives the same answer whichever way round you enter them.
CAGR
((new ÷ start)1 ÷ years − 1) × 100
Compound annual growth rate: the steady yearly rate that gets you from the start to the end. It smooths out the bumpy years in between.
The example charts
| Shared by | Measure | Start | End |
|---|---|---|---|
| Crossroads 2025-02-07 | Financial Services + Tech Platform Revenue (GAAP) (USD millions) | 2021: 253 | 2024: 1,217 |
| McFly 2025-10-04 | Current Large Load Interconnection Queue (MW) | 2022: 2,634 | 2024: 4,753 |
| Evan 2026-10-02 | NVIDIA Data-Center Revenue vs. Big Tech CAPEX (USD billions) | 2022: 10 | 2025: 47 |
| Dividendology 2026-09-14 | PE Ratio (Historical) | 2021: 33.64 | 2025: 73.84 |
| Fiscal.ai 2026-09-30 | MediaTek (TWSE: 2454) - Operating Income (Millions) | 2008: 647 | 2025: 3,296 |
Values are the numbers printed on each chart, read on 2026-10-14. Estimates and projections are left out. Not investment advice. See the stock charts
Questions people ask
How do I calculate percentage increase?
Subtract the starting value from the new value, divide by the starting value and multiply by 100. From 40 to 50 is (50 − 40) ÷ 40 × 100 = 25% increase.
What is the difference between percent change and percent difference?
Percent change has a direction: it measures from a starting value. Percent difference has none: it compares two values against their average, so swapping them gives the same answer.
Why is a 50% drop not undone by a 50% rise?
Because each percentage is taken from a different starting value. 100 down 50% is 50, and 50 up 50% is 75. To get back to 100 from 50 you need a 100% increase.
When should I use CAGR?
When the two numbers are more than a year apart and you want one yearly rate. Revenue going from 10 to 20 over 5 years is a 100% change but about 14.9% a year compounded.