Percentage Change Calculator

Free online percentage change calculator with step-by-step calculations.

Perfect for students, teachers, and professionals needing quick mathematical computations.

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How This Tool Works

The Percentage Change Calculator compares an original value with a new value and reports the relative change as a percentage. Enter the starting value in Original Value and the ending value in New Value; the calculator applies ((New - Original) / Original) x 100.

A positive result means the value increased, while a negative result means it decreased. For example, changing from 80 to 100 is ((100 - 80) / 80) x 100 = +25%.

  • Input: Original value and new value.
  • Output: Percentage increase or decrease.
  • Important: Percentage change is undefined when the original value is zero.

Frequently Asked Questions

Common questions about the Percentage Change Calculator

((New - Old) / Old) × 100. From 80 to 100: (100-80)/80 × 100 = 25% increase.

Sources & References

Mathematical functions and constants

Definitions, identities, and standard values for mathematical functions and constants used across these calculators.