How it works
Enter the original (starting) value and the new value. The calculator works out the percentage change between them — a positive result means an increase, a negative one means a decrease — and also shows the plain difference between the two numbers. It's the go-to for comparing prices, salaries, metrics, or any before-and-after figure. Because the change is measured relative to the starting value, the original can't be zero. Everything runs locally in your browser.
Percentage Change Calculator
Percent increase or decrease between two numbers.
FAQ
How is percentage change calculated?
Percentage change is the difference between the new and old value, divided by the absolute value of the old value, times 100. A positive result is an increase and a negative result is a decrease.
What if the original value is zero?
Percentage change is undefined when the starting value is zero, because you can't divide by zero. The tool will let you know instead of showing a misleading number.
What's the difference between percentage change and percentage points?
Percentage change is relative to the starting value. Percentage points measure the simple arithmetic gap between two percentages — for example, going from 10% to 15% is a 5 percentage-point rise but a 50% increase.
Is anything uploaded?
No. The calculation runs entirely in your browser. Nothing is sent to a server.
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