Percentage Change Calculator

Enter an old value and a new value to instantly see the percentage increase or decrease between them.

+20.00%Increase

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How to use

  1. Enter the old value.
  2. Enter the new value.
  3. Read the percentage change and whether it's an increase or decrease.

What is this tool?

Percentage Change Calculator works out how much a number has grown or shrunk, expressed as a percentage of the original value. Unlike a simple percentage-of calculator, this compares two values and tells you the relative change between them, live as you type.

Common uses

  • Working out how much a price, salary or metric has increased or decreased
  • Comparing month-over-month or year-over-year changes in a report
  • Checking the percentage growth of a number for a presentation
  • Understanding how significant a change between two figures really is

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FAQ

How is percentage change calculated?

It's the difference between the new and old value, divided by the absolute old value, multiplied by 100.

What does a negative result mean?

A negative percentage means the new value is smaller than the old value — a decrease.

What if the old value is zero?

Percentage change is undefined when the starting value is zero, since there's no baseline to compare against.