Percentage Increase/Decrease Formula

Problem

Calculating percentage change between two values is confusing and error-prone.

Solution

((New - Old) / Old) × 100. Positive = increase, negative = decrease.

Benefit

Universal formula for all percentage change calculations.

Example

Price increased from $50 to $65:
((65 - 50) / 50) × 100
(15 / 50) × 100 = 30% increase

Price decreased from $80 to $60:
((60 - 80) / 80) × 100
(-20 / 80) × 100 = -25% decrease